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**** DEMO Copy *** DEMO Copy *** DEMO Copy *** DEMO Copy **** * * * COMET-MP: the Background Communications Library * * * * by CompuSolve 88 Erie Ave Rockaway, NJ 07866 * * (201)983-9429 * ************************************************************* This manual and associated software for COMET-MP is provided as a demonstration/evaluation copy. It's only limitation is that file transfers are limited to 2k (2048 bytes) in size. Any file transfer commands encountering a file size that exceeds this 2k demo limit will automatically cancel. Once you're impressed with COMET's abilities you can order it directly from CompuSolve by phone (VISA-MC-AMEX) or send a check for $169 to receive the latest copy of the product and a manual. Of course we'll remove the 2k limit for those of you that order! COMET is sold ROYALTY FREE so the necessary COMET.BIN or linked COMET.OBJ can be included with all your applications at no additional cost. There are two versions of COMET available, a single port version called COMET and the multi-port version called COMET-MP which can support up to 5 COM ports simultaneously, all in the BACKGROUND. This demo package contains the COMET-MP version. The single port version sells for $99.00 . This manual has been generated with 66 lines/page. C O M E T - M P Copyright (c) 1989 - 1991 by CompuSolve All Rights Reserved CompuSolve 88 Erie Avenue Rockaway, NJ 07866 U.S.A. Tele: (201)983-9429 Support: (201)983-9429 BBS: (201)983-9426 FAX: (201)627-1028 rev 1.0 Table Of Contents Warranty ....................................... 1 License ........................................ 2 Technical Support .............................. 3 Installation ................................... 4 Introduction ................................... 5 Getting Started ................................ 6 Conventions .................................... 7-8 Commands - General ............................. 9 Commands: ARECV ........................................ 10 ARECVA ....................................... 10 ASEND ........................................ 11 BUFFER ....................................... 12,13 CLOSE ........................................ 14 DTR .......................................... 15 FCHK ......................................... 16,17 FIND ......................................... 18 FINDI ........................................ 18 FLAVOR ....................................... 19 FLUSH ........................................ 20 INPUT ........................................ 21,22 MSTAT ........................................ 23 ONDCD ........................................ 24,25 ONDONE ....................................... 26 ONTIME ....................................... 27 OPEN ......................................... 28,29 OUTPUT ....................................... 30 RTS .......................................... 31 RXCNT ........................................ 32 STAT ......................................... 33 TXCNT ........................................ 34 VERS ......................................... 35 XRECV ........................................ 36 XSEND ........................................ 37 YRECV ........................................ 38 YSEND ........................................ 39 Troubleshooting ................................ 40 Error Codes .................................... 41 Appendix A (Auxilary-Byte Table) ............... 42 Appendix B (Clipper Event Trapping Notes) ...... 43 WARRANTY Thank you for purchasing the COMET communication library! CompuSolve offers a no nonsense money back guarantee to original owner's of COMET. You may return the entire software package within the first 30 days of purchase for a full refund, for any reason. If you bought COMET directly from CompuSolve you'll need to call and get a return authorization number before sending any materials back. If purchased from a mail order firm or elsewhere you'll need to contact them directly for return information and policies. While every effort has been made to make COMET reliable and bug free, no software publisher can guarantee 100% bug free software. CompuSolve will make every effort to investigate bug reports, offer work around solutions and promptly offer software fixes at no additional charge. - 1 - LICENSE Compusolve grants the original purchaser an unlimited duration license to use COMET software under the following terms and conditions: 1) When developing application software using the COMET software library and associated manual, only one PC is to have COMET installed at any given time. Multiple copies of the COMET libraries and documentation are prohibited. 2) After developing an application, you are entitled to provide the COMET library file only along with the rest of your application's programs. For Clipper applications the COMET.OBJ library file is directly linked in to produce executable programs so no COMET files are to be distributed. Interpretative dBASE languages should only have the COMET.BIN library file distributed with the application programs. In no instance should the distributed COMET.BIN library file be renamed. Those not willing to agree to the above license terms should return COMET within the first 30 days of purchase for a full refund. - 2 - TECHNICAL SUPPORT Telephone: (201)983-9429 Phone support is free for the first 60 days to all registered owners. Beyond the first 60 days, there is a charge of $20 per call or a yearly support plan costing $55 (Amex, MC and VISA) Bulletin Board (BBS): (201)983-9426 Unlimited free technical support is available through the use of our 24 hour a day bulletin board. The board operates at 1200 or 2400 baud, 8 data bits, no parity and 1 stop bit (a perfect use for the sample terminal emulation program that's included with COMET). After logging on to the system, leave your questions or comments as E-mail to the SYSOP. FAX: (201)627-1028 Also, unlimited free support is provided when inquiries are directed to our FAX machine which is operative 24 hours a day. - 3 - INSTALLATION 1) Insert the COMET product diskette into any floppy drive. 2) Change to the hard disk directory where you want the COMET files to be installed using DOS's "CD" command. 3) Assuming you've put the COMET diskette in drive A, run one of the install programs listed below for your database language: A:CMETCLIP - Clipper (all versions) or A:CMETD3FX - dBASEIII, FoxBase, QuickSilver and compatibles or A:CMETD4FP - dBASEIV AND FoxPro Example 1: C: CD\CLIPPER A:CMETCLIP Example 2: D: CD\FOXPRO A:CMETD4FP Example 1 would install the Clipper version of COMET into the hard disk's C:\DATABASE directory whereas example 2 would install the dBASEIV/FoxPro version into D:\FOXPRO - 4 - INTRODUCTION COMET-MP is an add on communications library compatible with dBASEIII/IV, FoxBase/Pro, Clipper S87/5.0, dBXL and QuickSilver. COMET extends these database languages by adding powerful communications capabilities. One of COMET's most unique features is that all of its commands operate entirely in the background leaving your program free to do other tasks. No longer do you have to wait for lengthy file transfers to complete before being returned to your database application. Imagine a data entry person posting invoices while COMET handles incoming modem calls and performs file transfers, all in the background! COMET-MP (multi-port) supports the simultaneous use of upto 5 COM ports. With user defined I/O port addresses and interrupts, COMET-MP will work on virtually any IBM PC compatible RS232 hardware including boards manufactured by companies such as DigiBoard and AST Research. This manual assumes the reader is somewhat familiar with serial communications and its terminology (ie. baud rate, parity, COM port etc.). Those not familiar with such terms should refer to appropriate books on the subject. In addition, those intending to do modem communications are well advised to obtain a copy of the reference manual for their particular modem for an explanation of modem configurations and command sets. - 5 - Getting Started While COMET is primarily intended for use within a database program, it will also work from the dot prompt of any of the database languages with the exception of Clipper, as it is a compiled language (Clipper developers: link COMET with Nantucket's DOT.PRG to test from a dot prompt environment). In fact, using COMET from the dot prompt is one of the best ways for programmers to familiarize themselves with COMET. The following few lines demonstrate how easy it is to OPEN a COM port (COM1) with a Hayes compatible modem attached, then have the modem dial a number: . LOAD COMETMP && Not needed for Clipper . OpenCmd = 'OPEN COM1:2400,N,8,1,N' . CALL COMETMP WITH OpenCmd . Dial = 'OUTPUT #1,ATDT123-4567' + CHR(13) . CALL COMETMP WITH Dial Now we'll CLOSE COM1 and force modem to disconnect: . ClsCmd = 'CLOSE #1' . CALL COMETMP WITH ClsCmd In addition to testing COMET from the dot prompt, you may want to run and later examine the sample program TERMINAL.PRG which is a simple terminal emulation program demonstrating many of COMET's commands. NOTE: Clipper users will need to first compile and then link the sample program as follows: a) CLIPPER TERMINAL.PRG (compiles program) b) Using PLINK86 or RTLINK to link: =>FILE TERMINAL.OBJ, COMETMP.OBJ =>OUTPUT TERMINAL.EXE =>LIB CLIPPER, EXTEND - 6 - COMMANDS - CALLING CONVENTIONS The following section describes COMET's command set. All of the commands are invoked by using the CALL ... WITH command syntax supported by each database language. The basic format of the CALL statement is: CALL COMETMP WITH <varC> On Entry: <varC> is a character variable consisting of the following: 1) The name of the COMET command to perform (required) 2) Port#(1-5) followed by a comma (command dependent) 3) Command parameters/arguments (command dependent) On Return: In order to pass results or data back to the database program, COMET modifies a portion of <varC>'s contents after performing the requested command. Using a database SUBSTR function, one can extract the returned information from <varC>. This returned data always starts immediately after the comma which seperates the port # from the rest of the command parameters. NOTE: COMET will never increase the length of <varC> in order to return data. If <varC> is not long enough, COMET simply truncates the data being returned. If COMET increased <varC>'s length, the database language's internal variable memory map could be corrupted. Errors: If COMET is passed an invalid command name or parameter, then the first one or two characters of <varC> will be modified with an appropriate error code as detailed in appendix A. A simple way then to test whether COMET is reporting an error is to compare the first two letters of returned <varC> against the first two letters of the command name requested. NOTE: It is highly recommended that you implement a single procedure or function to do all CALLs to COMET. In addition to performing the actual CALL using the procedure's parameters, it should test for any COMET reported errors as described above. - 7 - COMMANDS - CALLING CONVENTIONS (cont'd) Example 1: * Open and initialize COM port #1 for use OpenCmd = "OPEN COM1:2400,N,8,1" CALL COMETMP WITH OpenCmd *Now test for an error by testing 1st two chars of OpenCmd OpenWasOK = IIF(OpenCmd = "OP", .T., .F.) *If OPENed ok, send text "Hello World" and CR/LF IF OpenWasOK OutputCmd = "OUTPUT #1,Hello World" + CHR(13) + CHR(10) CALL COMETMP WITH OutputCmd ELSE ? "COMET OPEN command failed!" ENDIF Example 2: *This code demonstrates the recommended way to perform all COMET *commands using a centralized CALLing procedure approach that *tests for COMET reported errors. OpenWasOk = COMET_CALL("OPEN COM1:2400,N,8,1") IF OpenWasOk OutputOk = COMET_CALL("OUTPUT #1,Hello World" +CHR(13) + CHR(10)) ELSE ? "COMET OPEN command failed!" ENDIF . . . FUNCTION COMET_CALL && PROCEDURE stmt if dBASEIII/FoxBase PARAMETERS CometCmd * Save 1st 2 letters of command name so we can test for errors Command1_2 = LEFT(CometCmd, 2) CALL COMETMP WITH CometCmd && Perform COMET command *Now see if COMET reported any errors Ok = IIF(CometCmd = Command1_2, .T., .F.) RETURN Ok && Return command success/failure - 8 - COMMAND REFERENCE FORMAT: The following describes notation conventions used throughout the command reference section of this manual. ENTRY: - Specifies the required syntax and format of the character type variable passed to COMET for a particular command. <varC> - The character type variable that must be passed following the WITH clause of the CALL statement. This character expression is usually a variable rather than a constant so that data or error messages from COMET can be retrieved. RETURN: - Specifies the contents of <varC> after COMET has updated the variable with any results/data being returned. [ ] - Used to indicate either optional command parameters that can be supplied upon entry, or data that might be returned by COMET depending on circumstances. The brackets are not part of <varC> unless explicitly stated for a given command. | - Means OR, indicating that 1 or more choices exist. eg. Expr1 | Expr2 means expression1 OR expression2 can be used. NOTE: Parameters that require numeric values as part of <varC> can be entered in decimal or hexadecimal format. Decimal is assumed by default unless a number is preceded by an "x" or "X". eg. 100 = decimal 100 x100 = decimal 256 (hex 0100) - 9 - COMMAND: ARECV and ARECVA ENTRY: <varC> = "ARECV|ARECVA #P, filespec [,timeout]" #P = desired port # (1-5) filespec = DOS path\filename timeout = # seconds before auto-close (0 - 3600) RETURN: <varC> unchanged unless error ERROR CODES: (See appendix A for general error codes) "xx" - port not OPEN "-" - busy (previous file transfer still active) SEE ALSO: ASEND, FCHK, FLUSH, OPEN PURPOSE: Used to begin capturing of incoming COM port data into a specified file. ARECV creates a new file overwriting any existing file of the same name, whereas ARECVA appends to an existing file. The optional timeout parameter specifies the duration of COM port receiver inactivity before automatically closing the file and canceling the capture. The default timeout is 60 seconds. Specify a value of 0 to disable auto-close feature. Other than a timeout, there are two other ways the file can be closed; if a DOS End-Of-File (EOF = 1Ah = 26d) character is received or a FLUSH command is given for this COM port. When capturing is in progress the COM port data can also be read from the receive buffer using the INPUT command. ARECV will use flow control to insure no data is lost if the OPEN command has specified either Xon/Xoff or Rts/cts methods. Use FCHK to determine the number of bytes captured at any time as well as determine if any data loss has occurred. Unlike the XModem and Ymodem commands, ARECV will allow OUTPUTting of data to the port even while capture is in progress. EXAMPLE: * Initiates capturing of port #1 data to a new file with a default * 60 second timeout. RecvCmd = 'ARECV #1,\MYDIR\MYFILE.RCV' CALL COMETMP WITH RecvCmd * Initiate capture, but append to existing file and no timeout. RecvCmd2 = 'ARECVA #1,\DBASE\CAPTURE.TXT,0' CALL COMETMP WITH RecvCmd2 - 10 - COMMAND: ASEND ENTRY: <varC> = "ASEND #P,filespec" #P = desired port # (1-5) filespec = DOS path\filename RETURN: <varC> = unchanged unless error ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN "-" = busy (file transfer already active) SEE ALSO: ARECV, FCHK, FLUSH, OPEN PURPOSE: Used to begin sending of a file out the specified COM port. No error checking protocol is used as the file is simply copied out the port. Use only when either errors can be tolerated (eg. text files), sender and receiver are directly wired together, or some type of error correcting modems are in use. Although this command is normally used to send ASCII rather than binary files, all characters will be sent including control characters. It is the size of the file that determines when ASEND completes. ASEND will respond to flow control if the port was OPENed with either Xon/Xoff or Rts/cts specified. Use FCHK to determine the number of bytes sent so far. Unlike the XModem and Ymodem commands, ASEND will allow INPUTting of data from the port even while sending is in progress. To cancel ASEND at any time, issue a FLUSH command. EXAMPLE: * Send a file out port #1 SendCmd = 'ASEND #1,\MYDIR\MYFILE' CALL COMETMP WITH SendCmd *Note how COMET returns immediately while file gets sent in the *background. *Some time later, get file status SendChk = 'FCHK #1,' + SPACE(80) CALL COMETMP WITH SendChk @ 24, 0 SAY SendChk && Display current status - 11 - COMMAND: BUFFER ENTRY: <varC> = "BUFFER #P, [seg: len]" #P = desired port # (1-5) seg = segment address for start of buffer len = length of buffer in bytes (must be > 1024d) RETURN: <varC> = unchanged unless error ERROR CODES: (See appendix A for general error codes) "?s" = Illegal/missing segment address "?l" = Illegal/missing length SEE ALSO: OPEN PURPOSE: This command allows the default buffer size and/or location to be overridden for the specified port. By default COMET reserves 1024 bytes for each port's buffer. This buffer space is used for: 1) All received data, including file receive operations 2) Data being transmitted, only for file send operations In some cases the 1024 byte buffer may be too small resulting in lost data as can be determined by FCHK's or RXCNT's buffer overflow error messages. In most buffer overflow cases though, the problem can easily be solved by specifying some form of flow control in the OPEN command. If the sending device doesn't support flow control, then increasing the buffer size may be the only solution. There are 2 ways to specify a custom buffer location/size: All Languages: If a segment address and buffer length are given, COMET will use memory starting at seg:0000 for a length of len bytes for the port's buffer. No checking is done to see if this memory requested conflicts with other programs, so be sure the region specified is unused. This allows one to create very large buffers in DOS's high memory area without reducing the amount of conventional memory available to DOS and programs. The largest length for any one buffer is 64k (65536 bytes). Clipper ONLY: If only a length parameter is passed, COMET will request a memory block from DOS that is len bytes long. eg. <varC> = "BUFFER #1, x1000" will attempt to establish a new buffer that is 1000h (4096d) bytes in size. - 12 - COMMAND: BUFFER (cont'd) EXAMPLE: *Method 2 - create new buffer starting at C000:0000 for 8000 *bytes (8000 decimal, could also have been x2000) HiMemBuff = "BUFFER #1, xC000: 8000" CALL COMETMP WITH HiMemBuff NOTE: Segment and length values may be in either heXidecimal or decimal format. Hexadecimal numbers must be preceded by an upper or lowercase x. When a port gets CLOSEd, any custom buffer information is lost and must be specified again after the port is once again OPENed. - 13 - COMMAND: CLOSE ENTRY: <varC> = "CLOSE [#P]" #P = desired port # (1-5) RETURN: <varC> = unchanged ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN SEE ALSO: FLUSH, OPEN PURPOSE: To shut down one or all currently OPENed COM ports. If no #P parameter specified, then all OPEN ports will be closed and no longer available until reOPENed. Any ports closed will have their respective Data Terminal Ready (DTR) and Clear-To-Send (CTS) outputs turned off. Additionally, if the port(s) have active file transfers going on, these will be terminated and files closed. It is a good practice to issue the CLOSE command before exiting or QUITing from your database program, even though COMET automatically closes ports and files when exiting. EXAMPLE: * Let's shut down just port #4 Clos4 = "CLOSE #4" CALL COMETMP WITH Clos4 * Let's shut down all OPEN ports ClosAll = 'CLOSE' CALL COMETMP WITH ClosAll - 14 - COMMAND: DTR ENTRY: <varC> = "DTR #P,n" #P = desired port # (1-5) n = 0 or 1 RETURN: <varC> = unchanged PURPOSE: To set the state of the COM port's Data Terminal Ready (DTR) output signal. Specify 1 to set the signal active, 0 to disable. By default, the signal is set to an active (1) state after the COM port is OPENed. Data Terminal Ready is output from the PC's serial COM port to whatever device is attached to the port. If a modem is attached, this signal is normally required to be at an active (1) state before the modem will respond to any commands it receives. Furthermore most Hayes compatible modems will automatically disconnect from the telephone line if Data Terminal Ready should change from a 1 to a 0 state during a call. With modems then, the DTR command is a simple way to force a modem to disconnect or hangup. EXAMPLE: DTROn = 'DTR #2,1' DTROff = 'DTR #2,0' CALL COMETMP WITH DTROn && Set DTR active CALL COMETMP WITH DTROff && Now, turn DTR off NOTE: Some modems have a dip switch or configuration setting that can override the Data Terminal Ready disconnect feature. Consult your modem's manual for details. - 15 - COMMAND: FCHK ENTRY: <varC> = "FCHK #P," + SPACE(80) #P = desired port # (1-5) RETURN: <varC> = "FCHK #P,prot,dir,stat,size,file [warn][fail]" prot = "ASCII ", "XMODEM" or "YMODEM" ( 9, 6) dir = "RECEIVE " or "TRANSMIT" (16, 8) stat = "ACTIVE ", "COMPLETE" or "FAILED " (25, 8) size = "#######" (bytes rec'd or sent) (34, 7) file = path\name of file (42, ?) [warn] = [DATA LOSS] [fail] = [CANCELED], [DATA ERRORS], [FILE: OPEN READ], [FILE: WRITE], or [TIMEOUT] ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN SEE ALSO: ARECV, ASEND, XRECV, XSEND, YRECV, YSEND PURPOSE: To determine the file transfer status of a specified port. FCHK reports the active file transfer protocol, direction, status, size in bytes transfered so far, file path/name and possible warning or failure messages. Except for the possible warning and failure messages, each value returned has a fixed starting position and length within <varC> to simplify extracting when using the SUBSTR function. Note that both the delimiting commas and brackets are returned in <varC>. Once FCHK reports a finished status (ie. COMPLETE or FAILED), subsequent calls to FCHK will report the word "IDLE" to indicate that no file transfer is active until another file transfer command gets issued. Since COMET does not directly display file transfer status, one use for FCHK would be to periodically display this status. Used in conjunction with the ONTIME command, it is possible to automatically do a procedure that displays current FCHK values every so often. When FCHK reports a FAILED status, [fail] will contain one of the following messages indicating the reason for failure: [CANCELED] - File transfer got canceled by either a FLUSH command or receiver/sender requested cancel. [DATA ERRORS] - Too many data related errors occurred probably due to noisy phone line when modems are involved. [FILE: OPEN/READ] - Couldn't open requested file or a non recoverable disk read error. [FILE: WRITE] - Non recoverable disk write error [TIMEOUT] - Receiver/sender fails to respond. With ARECV, indicates no data has been received for 60 seconds or user specified timeout value. - 16 - COMMAND: FCHK (cont'd) In addition, a warning message of "[DATA LOSS]" may be returned if the file protocol was ARECV and data was lost due to buffer overflow. If this warning occurs, you may need to implement some form of flow control for this port (see OPEN). NOTE: The length of <varC> required to fit all of FCHK's returned values will vary depending on the file path/name. Be sure to allow sufficient space or COMET will truncate items. EXAMPLE: StatCmd = 'FCHK #1,' + SPACE(80) CALL COMETMP WITH StatCmd Stus = SUBSTR(StatCmd,25,8) && Extract status Cnt = SUBSTR(Statcmd,34,7) && Extract byte count Last3 = SUBSTR(StatCmd,42) && File name + [fail] + [warn] SpcAt = AT(' ',Last3) && Find space after path\file name FName = SUBSTR(Last3,SpcAt-1) && Now we have path\file name @ 24,0 SAY 'File:' + FName @ 24,15 SAY 'Status: ' + Stus @ 24,30 SAY '# Bytes: ' + Cnt . - 17 - COMMAND: FIND and FINDI ENTRY: <varC> = "FIND|FINDI #P, string" #P = desired port # (1-5) string = character(s) to find RETURN: <varC> = "FIND|FINDI #P,?string" ? = plus sign(+) if string found; space if not found ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN PURPOSE: To search COMET's receive buffer for a character string. If string is found, the space character following #P, will be replaced with a plus sign character, "+". The FINDI form of the command specifies a case Insensitive search. If found, the buffer pointer advances to the first character of string essentially skipping over any characters prior to string that hadn't been read from the buffer. This leaves the buffer pointer set so that the next INPUT command would return data starting with string. If string can't be found, <varC> will remain unchanged so that the repeated CALLs to COMETMP can be made with the same <varC> until a "+" is reported. EXAMPLE: * Assume buffer holds: "abcdeFghijk" * Do a case insensitive search for "DEF" FindCmd = "FINDI #1, DEF" * Stay in a loop till "DEF" found DO WHILE .NOT. '+' $ FindCmd && Loop till found CALL COMETMP WITH FindCmd ENDDO * FindCmd now = "FINDI #1,+DEF" * FIND moved pointer so buffer now holds: "deFghijk" * Now let's read in upto 10 chars from buffer * COMET replaces the xxxxx with the # chars returned from buffer Inp = "INPUT #1, xxxxx" + SPACE(10) CALL COMETMP WITH Inp * Inp now = "INPUT #1, 00008deFghijk " NOTE: <varC> must contain a space after #P, which will be a place holder for the plus sign if string is found. This space is not going to be included in the search. The 1st character of the search string is always the second character after the comma. - 18 - COMMAND: FLAVOR ENTRY: <varC> = "FLAVOR fl" fl: C7 = Clipper, summer 87 C5 = Clipper 5.0 D3 = dBASEIII D4 = dBASEIV FB = FoxBase FP = FoxPro QS = QuickSilver or dBXL RETURN: <varC> = unchanged unless error ERROR CODES: ?f = illegal/missing value for language flavor SEE ALSO: ONDCD, ONDONE, ONTIME PURPOSE: To specify the database language or flavor being used with COMET. This information is used by COMET internally in situations where different courses of action need to be taken for certain languages. Currently, only dBASEIV users need to use this command as the ON... event trapping commands will not work reliably under dBASEIV unless the flavor is set to D4. In future versions of COMET more language specific situations may arise so it is highly recommended that the proper FLAVOR command be the first command CALLed. EXAMPLE: * Specify dBASEIV flavor MyFlav = "FLAVOR D4" CALL COMETMP WITH MyFlav - 19 - COMMAND: FLUSH ENTRY: <varC> = "FLUSH #P" RETURN: <varC> = unchanged ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN PURPOSE: This command performs several actions. First, it always empties out the COM port receive buffer and clears any paused condition due to flow control. Secondly, if any type of file transfer is in progress, it gets canceled. FCHK will report the status as CANCELED in this instance. This is a simple way to cancel any active file transfer, regardless of type. Also used to clear the buffer to a known empty state. EXAMPLE: * Start an XModem file send Send = "XSEND #1,\DBF\SALES.DBF" * Allow user to cancel file send by hitting ESC key Flsh = 'FLUSH #1' ON ESCAPE CALL COMETMP WITH Flsh SET ESCAPE ON - 20 - COMMAND: INPUT ENTRY: <varC> = "INPUT #P,?????" + SPACE(cnt) [ + CHR(t)] #P = desired port # (1-5) cnt = # of chars to get from buffer (maximum) t = optional input termination character's value RETURN: <varC> = "INPUT #P,nnnnndd .. d" nnnnn = # characters read from buffer and returned dd ..d = COM port data ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN "-" = busy (file transfer active) SEE ALSO: OUTPUT, RXCNT PURPOSE: To read data from specified COM port's receive data buffer. The amount of data that will be returned is controlled by several factors: 1) The length of <varC> determines the maximum number of characters that can be returned. This amount is limited to cnt characters if no termination character specified, cnt + 1 if a termination character is specified. 2) If a termination character is specified and this character is present within the buffer's data, only data upto and including the termination character will be returned leaving the buffer pointer at the character following the terminator. 3) If no data is waiting in buffer or all of it has been written into <varC> without encountering conditions 1 or 2, COMET will exit the INPUT command. <varC>'s nnnnn will reflect the number of characters that COMET has returned. This decimal number will always be 5 digits and left zero filled immediately followed by the returned data. EXAMPLE: * Assume buffer contains: "Hello World" + Cr + Lf * Let's read just the first 3 chars RdInp = "INPUT #1,?????" + SPACE(3) CALL COMETMP WITH RdInp * RdInp now = "INPUT #1,00003Hel" Cnt = VAL(SUBSTR(RdInp,10,5)) && Get # chars returned = 3 Data = SUBSTR(RdInp,15,Cnt) && "Hel" * Now let's find out how many more chars are in buffer and INPUT * them all. CntLeft = "RXCNT #1, " && Get count of # chars left in buff CALL COMETMP WITH CntLeft * Now CntLeft = "RXCNT #1,00010" CntLeft = VAL(SUBSTR, CntLeft, 10) - 21 - COMMAND: INPUT (cont'd) * INPUT, specifying a Lf, CHR(10), termination character RdInp2 = "INPUT #1,?????" + SPACE(CntLeft) +CHR(10) CALL COMETMP WITH RdInp2 * Now RdInp = "INPUT #1,lo World" + Cr + Lf - 22 - COMMAND: MSTAT ENTRY: <varC> = "MSTAT #P," + SPACE(18) #P = desired port # (1-5) RETURN: <varC> = "MSTAT #P,?DCD ?RI ?DSR ?CTS" ? = plus sign (+) if active, minus sign (-) if inactive ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN PURPOSE: To determine the state of the four modem status input signals at the specified COM port. The command always returns the four signal abbreviations with each one preceded by either a plus or minus sign to indicate active or not. This command can be called repetitively to poll the port's status for a desired state, such as testing for modem connect by waiting for "+DCD" to be returned. SIGNALS: PIN# 25 PIN CONN 9 PIN CONN DCD - Data Carrier Detect ............... 8 1 RI - Ring Indicator .................... 22 9 DSR - Data Set Ready .................... 6 6 CTS - Clear To Send ..................... 5 8 EXAMPLE: * Let's have a modem dial a # DialCmd = "OUTPUT #1,ATTD555-1212" + CHR(13) CALL COMETMP WITH DialCmd * And now we'll wait till DCD goes active indicating our modem * has connected MdmStat = "MSTAT #1," + SPACE(18) DO WHILE .NOT. '+DCD' $ MdmStat && Wait for DCD CALL COMETMP WITH MdmStat ENDDO - 23 - COMMAND: ONDCD ENTRY: <varC> = "ONDCD #P,a,x" #P = desired port # (1-5) a = key's ASCII code value Specify 0 if key has no ASCII value (ie. F1) x = key's auXilary-byte value (see appendix B). Specify 0 if key has an ASCII value. RETURN: <varC> = unchanged ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN SEE ALSO: ONDONE, ONTIME, MSTAT PURPOSE: This event trap command instructs COMET's background process to signal the database program whenever a change in the Data Carrier Detect (DCD) input signal occurs at the specified port. COMET does this by stuffing a user specified keystroke directly into DOS's keyboard buffer whenever a transition in the DCD signal occurs. This keystroke is defined by specifying the key's ASCII and auxilary byte values (see appendix B). To force the database program to execute a specific procedure in response to the DCD event, the program should have previously set up an appropriate key trap command (ie. ON ESCAPE, ON KEY n, or SET KEY n). This provides an easy way for a program to automatically jump to a special procedure whenever a modem connects or disconnects. Use MSTAT to determine whether DCD is active or inactive. EXAMPLE: ********* Clipper example code ******************** * Tell Clipper to DO DCDProc if F10 key entered SET KEY -9 TO DCDProc * Have COMET stuff F10 key if DCD at port #1 changes DCDCmd = 'ONDCD #1,0,68' && ASCII & Aux-Byte for F10 CALL COMETMP WITH DCDCmd ******** dBASE, Fox, dBXL or QuickSilver *********** ON ESCAPE DO DCDProc SET ESCAPE ON * Have COMET simulate ESC key if DCD changes at port #1 DCDCmd = 'ONDCD #1,27,0' CALL COMETMP WITH DCDCmd * main application code goes here - 24 - COMMAND: ONDCD (cont'd) PROCEDURE DCDProc * Get current DCD state COMStat = 'MSTAT #1' + SPACE(18) CALL COMETMP WITH COMStat && Chk if DCD + or - IF '+DCD' $ COMStat DO HaveDCD && A proc that might do file transfers ELSE DO LostDCD && A Proc that deals with disconnects ENDIF RETURN NOTE: To disable DCD event trapping don't specify any key parameters (ie. <varC> = "ONDCD #1") . dBASEIV: Set FLAVOR command to D4 CLIPPER USERS: See notes in appendix B - 25 - COMMAND: ONDONE ENTRY: <varC> = "ONDONE #P,a,x" #P = desired port # (1-5) a = key's ASCII code value. Specify 0 if key has no ASCII value (ie. F1) x = key's auXilary-byte value (see appendix B). Specify 0 if key has an ASCII value. RETURN: <varC> = unchanged error ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN SEE ALSO: ONDCD, ONTIME, FCHK PURPOSE: This command instructs COMET's background process to signal the database program whenever a file transfer is done, either due to normal completion or failure. COMET does this by writing the ASCII and auxilary bytes values specified directly into DOS's keyboard buffer. To force the database program to execute a specific procedure when a file transfer is done, the program should have previously set up an appropriate key trap command (ie. ON ESCAPE, ON KEY n, or SET KEY n). EXAMPLE: ********* Clipper example code ******************** * Tell Clipper to DO DoneProc if S/F10 entered SET KEY -19 TO DoneProc * Have COMET simulate S/F10 upon file completion/failure DoneCmd = 'ONDONE #1,0,93' && ASCII & Aux-Byte for S/F10 CALL COMETMP WITH DoneCmd ******** dBASE, Fox, dBXL or QuickSilver *********** ON ESCAPE DO DoneProc SET ESCAPE ON * Have COMET simulate ESC key upon file completion DoneCmd = 'ONDONE #1,27,0' CALL COMETMP WITH DoneCmd * * main application code goes here * PROCEDURE DoneProc * Let's disconnect after file transfer is done HangUp = 'DTR #1,0' CALL COMETMP WITH HangUp && Modem disconnect RETURN NOTE: To disable ONDONE event trapping, don't specify any key parameters (ie. <varC> = "ONDONE #1"). CLIPPER USERS: See notes in appendix B dBASEIV: Set FLAVOR to D4 - 26 - COMMAND: ONTIME ENTRY: <varC> = "ONTIME t,a,x" t = time interval in seconds between events a = key's ASCII code value. Specify 0 if key has no ASCII value (ie. F1) x = key's auXilary-byte value (see appendix B). Specify 0 if key has an ASCII value. RETURN: <varC> = unchanged unless error ERROR CODES: (See appendix A for general error codes) SEE ALSO: ONDCD, ONDONE PURPOSE: This command instructs COMET's background process to signal the database program every t seconds. COMET does this by writing the ASCII and auxilary bytes values specified directly into DOS's keyboard buffer. To force the database program to execute a specific procedure every t seconds, the program should have previously set up an appropriate key trap command (ie. ON ESCAPE, ON KEY n, or SET KEY n). EXAMPLE: ********* Clipper example code ******************** * Tell Clipper to DO TimeProc if S/F10 entered SET KEY -19 TO TimeProc * Have COMET simulate S/F10 every 5 seconds TimeCmd = 'ONTIME 5,0,93' && ASCII & Aux-Byte for S/F10 CALL COMETMP WITH TimeCmd ******** dBASE, Fox, dBXL or QuickSilver *********** ON ESCAPE DO TimeProc SET ESCAPE ON * Have COMET simulate ESC key upon file completion TimeCmd = 'ONTIME 5,27,0' CALL COMETMP WITH TimeCmd * * main application code goes here * PROCEDURE TimeProc * * This procedure will execute every 5 seconds * RETURN NOTE: To disable ONTIME event trapping, don't specify any parameters (ie. <varC> = "ONTIME"). CLIPPER USERS: See notes in appendix B dBASEIV: Set FLAVOR to D4 - 27 - COMMAND: OPEN ENTRY: <varC> = "OPEN COMn[,a,i]:b,p,d,s[,f]" n = com port # to open ( 1 - 5) a = optional port hardware I/O address i = optional port hardware interrupt IRQ# (2-7) b = baud rate (300 - 38400) p = parity None, Even or Odd (N, E or O) d = # data bits (7 or 8) s = # stop bits (1 or 2) f = flow control; Xon/Xoff, Rts/cts, or None (X, R or N) ERROR CODES: (See appendix A for general error codes) "-" = busy "?p" = invalid parity "?n" = invalid port # "?f" = invalid flow control "?a" = invalid address "?d" = invalid # data bits "?i" = invalid IRQ# "?s" = invalid # stop bits "?b" = invalid baud rate PURPOSE: To prepare or initialize the desired COM port to the specified settings. A port must be OPEN before other commands can use it. IMPORTANT: COMET needs to know several hardware specific details about each COM port that is to be OPENed. First, it needs to know the base I/O (input/output) address of the port so COMET knows where to read and write data from/to. Secondly, COMET needs to know what interrupt line, or IRQ#, this port will use to "signal" COMET when the port needs to be serviced. COMET needs to be signaled when important events occur (ie. a character has just been received or the port is able to send a character). If you are using an industry standard COM1 or COM2 as defined by the table on the following page, you don't need to specify any I/O address or IRQ# parameters as COMET will use these default values. While there are industry standards for COM3 and COM4 as far as I/O addresses, no standard exists as to what IRQ#'s are to be used. If your COM3 or COM4 conforms to the table below, you need not specify any address or IRQ# parameters as the defaults will be used. If your using non standard COM ports (ie. third party serial boards like DigiBoard or AST Research), you need to specify the I/O address and IRQ# parameters in the OPEN command. Note that while each port must have a unique I/O address, ports can share the same interrupt IRQ#. This allows multi-port boards that might have only 1 or 2 interrupt lines to work with COMET. When specifying these parameters, the actual COM port number parameter, n, can be any value from 1 to 5. The COM port number parameter, n, serves two purposes. First, if no I/O address and IRQ# parameters are present, COMET uses the default values for the specified port number n based on the table on the following page. Secondly, it serves a port identifier for all other COMET commands which need to indicate a port. - 28 - COMMAND: OPEN (cont'd) Default Addresses and Interrupts: COMn Address (hex) IRQ# ---- ------------- ---- 1 x03F8 4 2 x02F8 3 3 x03E8 3 4 x02E8 3 EXAMPLE: * Let's OPEN port 1 as industry standard COM1 at 2400 baud, no * parity, 8 data bits, 1 stop bit and no flow control. OpenCmd = "OPEN COM1:2400,N,8,1,N" CALL COMETMP WITH OpenCmd * Let's open port 1 with custom base address of 0100 hex using * interrupt IRQ #7 and using Xon/xoff flow control. OpenCmd = "OPEN COM1,x0100,7:2400,N,8,1,X" NOTE: While each port OPENed must have a unique I/O address, it may share the same interrupt IRQ# with upto four other ports allowing upto five ports to use only one IRQ. Third party multi port boards will typically only offer 1 or 2 interrupt IRQs for all their ports to share. - 29 - COMMAND: OUTPUT ENTRY: <varC> = "OUTPUT #P,string" #P = desired port # (1-5) string = character(s) to output RETURN: <varC> = unchanged ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN "-" = busy (file transfer active) SEE ALSO: INPUT, TXCNT PURPOSE: To output character(s) to the specified serial COM port. If Xon/xoff or Rts/cts flow control was specified at OPEN time, COMET will monitor and pause output when receiver sends an Xoff character or lowers its CTS signal. Use TXCNT command to determine output status. EXAMPLE: * Let's output a dial command to Hayes type modem OUTCmd = 'OUTPUT #2,ATDT(111)222-3333' + CHR(13) CALL COMETMP WITH OUTCmd NOTE: A null (binary 0) character can't be part of <varC> since its reserved to indicate or mark the end of character strings in the database environment. To have COMET output a null, don't specify any string parameter. eg. <varC> = "OUTPUT #1," will output a single null character. - 30 - COMMAND: RTS ENTRY: <varC> = "RTS #P,n" #P = desired port # (1-5) n = 0 or 1 RETURN: <varC> = unchanged ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN PURPOSE: To set the state of the COM port's Request To Send (RTS) output signal. This signal is set active (1) by default as soon as the COM port gets OPENed. RTS can also change states if RTS/CTS handshaking was specified in the OPEN command and the receive buffer approaches 80% full in which case RTS goes low (0). Similarily, as the buffer empties to 20% of capacity the RTS signal will go active (1). The buffer's default capacity is 1024 characters but may be overridden with the BUFFER command. EXAMPLE: * Let's turn RTS on and then off at port #3 RTSOn = 'RTS #3,1' RTSOff = 'RTS #3,0' CALL COMETMP WITH RTSOn && Set RTS active/on CALL COMETMP WITH RTSOff && Turn RTS off - 31 - COMMAND: RXCNT ENTRY: <varC> = "RXCNT #P," + SPACE(5) #P = desired port # (1-5) RETURN: <varC> = "RXCNT #P,n[nnnn][*]" n[nnnn] = # bytes waiting in receive buffer * = buffer overflow indicator ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN PURPOSE: To determine how many characters are pending in the receive buffer. The default capacity of this buffer is 1024 characters but may be set to any size from 1024 to 65536 bytes. No leading zeroes or spaces are returned for n. This command is useful when you want to determine if a certain amount of data has arrived to the COM port. If RXCNT returns an asterisk following the count, this is an indication that the receive buffer for this port has overflowed. Data has not been INPUT from the port frequently enough to make room for new incoming data. Try enabling some form of flow control in the OPEN command to correct this problem. EXAMPLE: * Assume that data is sent to port #2 in a block fashion (ie. a * constant throughput). Let's determine when sender has finished * sending a block by waiting for RXCNT's value to level off. * We'll consider 1 second of no received data to indicate end of * block. LastRxCnt = GetRxCnt(2) && Init to current cnt in buffer NoRxSince = SECONDS() && Init secs cntr DO WHILE SECONDS() - NoRxSince < 1 CurrRxCnt = GetRxCnt(2) IF CurrRxCnt # LastRxCnt && Compare current RXCNT vs last NoRxSince = SECONDS() && Got rec'd data, reset secs cntr LastRxCnt = CurrRxCnt && Update buff cnt ENDIF ENDDO . . . FUNCTION GetRxCnt && dBASEIII should use PROCEDURE stmt PARAMETERS PortN PortC = STR(PortN) GetCnt = "RXCNT #" + PortC + "," + SPACE(5) && Build RXCNT <varC> CALL COMETMP WITH GetCnt RETURN VAL(SUBSTR(GetCnt,10)) && Return cnt of # chars in buffer - 32 - COMMAND STAT: ENTRY: <varC> = "STAT #P," + SPACE(3) #P = desired port # (1-5) RETURN: <varC> = "STAT #P,???" ? = F, P or O (Framing, Parity or Overrun UART errors) PURPOSE: To read the line status of specified port's UART (Universal Asynchronous Receiver/Transmitter) chip. In simple terms, this command reports on three classes of hardware detected errors for a given port #: Framing, Parity and receiver Overrun errors. Parity errors indicate that the UART has reported one or more received characters with parity bit errors since the last time the STAT command was issued. Overrun errors indicate that COMET has failed to read a received character from the UART before the next character arrived (ie. overran the UART's internal 1 character buffer). For further information on UART errors please refer to technical books on serial communications. COMET clears this error information every time this STAT command is issued. EXAMPLE: UARTStat = "STAT #1, " CALL COMETMP WITH UARTStat UARTErrs = SUBSTR(UARTStat,9) && Get error codes, if any - 33 - COMMAND: TXCNT ENTRY: <varC> = "TXCNT #P," + SPACE(5) #P = desired port # (1-5) RETURN: <varC> = "TXCNT #P,n[nnnn]" n[nnnn] = # bytes waiting in receive buffer ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN PURPOSE: To determine how many characters are pending in the transmit buffer (non file related only). Since COMET uses the actual <varC> memory variable for buffering, there is no fixed size or location for a port's transmit buffer. No leading zeroes or spaces are returned for n. - 34 - COMMAND: VERS ENTRY: <varC> = "VERS" + SPACE(20) RETURN: <varC> = "VERS #.##" #.## is current COMET revision # PURPOSE: To get the version and revision level of the COMET library in use. EXAMPLE: Version = 'VERS ' CALL COMETMP WITH Version ? 'COMET version in use is: ' + Version - 35 - COMMAND: XRECV ENTRY: <varC> = "XRECV #P,filespec" #P = desired port # (1-5) filespec = complete DOS path\filename RETURN: <varC> = unchanged unless error ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN "-" = busy (file transfer already active) SEE ALSO: XSEND, FCHK PURPOSE: To start receiving a file using the XMODEM or XMODEM/CRC protocol. XMODEM/CRC is always attempted first with the sender. Should the sender not support CRC, this command will fall back to the less reliable checksum method of error detection. Since XRECV operates in the background, use FCHK to determine the status of the file transfer at any time. Since the XMODEM protocol handles the synchronization of sender and receiver data blocks, no flow control need be specified when the port is OPENed. Any flow control specified for port is ignored during the file send operation. EXAMPLE: XmdmRecv = 'XRECV #1,C:\MYDIR\MYFILE.EXT' CALL COMETMP WITH XmdmRecv && Begin receiving file * * Any code here executes at the same time as file is being received * - 36 - COMMAND: XSEND ENTRY: <varC> = "XSEND #1,filespec" #P = desired port # (1-5) filespec = complete DOS path\filename RETURN: <varC> = unchanged ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN "-" = busy (file transfer already active) PURPOSE: To begin sending of a file using the XMODEM protocol. This command supports both CRC and checksum methods of error detection. The method used will depend on what the receiver requests at the start of the file transfer. Since this command operates in the background, use FCHK to obtain the file transfer status at any time. Any flow control settings for this port are ignored as the XMODEM protocol handles sender/receiver synchronization. EXAMPLE: XmdmSnd = 'XSEND #1,\MYDIR\MYFILE.EXT' CALL COMETMP WITH XmdmSnd * * Any code here executes while file is sent * - 37 - COMMAND: YRECV ENTRY: <varC> = "YRECV #P" #P = desired port # (1-5) RETURN: <varC> = unchanged unless error ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN "-" = busy (file transfer already active) PURPOSE: To begin receiving of a file or group of files using the YMODEM batch protocol. No filename is required as the YMODEM batch protocol includes a filename along with data for each file received. Any files received will be written to the current directory. Using YMODEM batch is superior to XMODEM for several reasons. First, the block size is 1024 bytes in YMODEM versus 128 in XMODEM. This larger block size yields a greater transfer rate than XMODEM. Secondly, YMODEM batch allows the use of DOS wildcard characters in the filespec parameter. This means a group of files can be received with one YRECV command, provided that the sender requested multiple files. Since this command operates in the background, use FCHK to determine the file transfer status at any time. EXAMPLE: YmdmRecv = 'YRECV #1' CALL COMETMP WITH YmdmRecv && Begin receiving file(s) * * Any code here executes while file(s) are received * NOTE: If the sender is using some type of a communications package such as XTALK or ProCom, make sure it is configured for and supports the YMODEM batch protocol. Some packages claim YMODEM capability, yet don't support the batch version. - 38 - COMMAND: YSEND ENTRY: <varC> = "YSEND #P,filespec" #P = desired port # (1-5) filespec = DOS path\filespec RETURN: <varC> = unchanged unless error code ERROR CODES: (See appendix A for general error codes) "xx" = port not OPEN "-" = busy (file transfer already active) PURPOSE: To begin sending a file or group of files using the YMODEM batch protocol. The filespec parameter can include wildcard characters so that more than one file can be sent within a single command. Since this command operates in the background, use FCHK to obtain the file transfer status at any time. EXAMPLE: YmdmSnd = 'YSEND \MYDIR\*.DBF' CALL COMETMP WITH YmdmSnd && Send all files with DBF extension * * Any code here executes during file send(s) * - 39 - TROUBLESHOOTING ----------------- Problem: After OPENing a port, I can only OUTPUT data to it. RXCNT and INPUT report 0 characters in buffer: Solution: Verify that your hardware uses the default IRQ# assumed by the OPEN command for COMn. If you've overridden the default IRQ#, verify its correctness with your serial port's user's manual. Problem: Using ARECV or ASEND, some data is lost during the transfer. Solution: The receiving PC probably cannot keep pace with the sender causing the buffer to overflow. Use some form of flow control by specifying Xon/xoff or Rts/cts in the OPEN command. Problem: I am trying to get a HAYES modem to dial a phone number by using COMET's OUTPUT command to send it a command string. The modem never seems to go off hook and dial the number. Solution: 1) HAYES modem will abort commands (including dialing) if you OUTPUT anything while they are still processing the original command string you sent. A general rule of thumb is to wait about 1 second between OUTPUTting of modem commands. 2) Did your OUTPUT <varC> end with a CHR(13) as required by all HAYES style modems? If not, the modem will just sit there idly. Problem: I am using FoxPro and sometimes my PC hangs when exiting FoxPro to DOS. Solution: Try disabling expanded memory by putting the following statement in your CONFIG.FP file: EMS=OFF This situation occurs very seldom and only when FoxPro loads the COMETMP.BIN file into EMS. Upon shutdown, FoxPro releases all EMS preventing COMET from doing its own shutdown. To avoid this problem and still be able to use EMS, simply make sure you CLOSE all COM ports before QUITing from FoxPro. A future release of COMET will correct this anomaly. - 40 - APPENDIX A - ERROR CODES After CALLing COMETMP with a character type variable, <varC>, COMETMP will return any error information by replacing the first one or two characters of <varC> with an error code from the following list: CODE ERROR DESCRIPTION ---- ---------------------------------------------------- ? Command name syntax error. Unknown command requested. ?# Illegal/missing port #. ?, Required comma delimiter missing. ?? Command requires parameters but none were found. xx Port # specified is not currently OPENed. - Specified port is busy at this time. Probably due to a file transfer that is still active. ?l Bad or missing parameter l. eg. CALLing COMETMP WITH "OPEN COM8:2400,N,8,1" for <varC> will return a "?n" error code indicating a bad parameter n for the OPEN command. - 41 - Appendix B: Auxilary-Byte Table ------------------------------- Value Key Value Key Value Key ----- ------- ----- ------- ----- --------- 59 F1 110 Alt-F7 44 Alt-Z 60 F2 111 Alt-F8 45 Alt-X 61 F3 112 Alt-F9 46 Alt-C 62 F4 113 Alt-F10 47 Alt-V 63 F5 48 Alt-B 64 F6 120 Alt-1 49 Alt-N 65 F7 121 Alt-2 50 Alt-M 66 F8 122 Alt-3 67 F9 123 Alt-4 15 Shift-Tab 68 F10 124 Alt-5 125 Alt-6 71 Home 84 Shift-F1 126 Alt-7 72 Up Arr 85 Shift-F2 127 Alt-8 73 PgUp 86 Shift-F3 128 Alt-9 87 Shift-F4 129 Alt-0 75 Left Arr 88 Shift-F5 130 Alt-Hyphen 89 Shift-F6 131 Alt-= 77 Right Arr 90 Shift-F7 91 Shift-F8 16 Alt-Q 79 End 92 Shift-F9 17 Alt-W 80 Down Arr 93 Shift-F10 18 Alt-E 81 PgDn 19 Alt-R 82 Insert 94 Ctrl-F1 20 Alt-T 83 Delete 95 Ctrl-F2 21 Alt-Y 96 Ctrl-F3 22 Alt-U 114 Ctrl-PrtSc 97 Ctrl-F4 23 Alt-I 115 Ctrl-Lft 98 Ctrl-F5 24 Alt-O 116 Ctrl-Rgt 99 Ctrl-F6 25 Alt-P 117 Ctrl-End 100 Ctrl-F7 118 Ctrl-PgDn 101 Ctrl-F8 30 Alt-A 119 Ctrl-Home 102 Ctrl-F9 31 Alt-S 103 Ctrl-F10 32 Alt-D 132 Ctrl-PgUp 33 Alt-F 104 Alt-F1 34 Alt-G 105 Alt-F2 35 Alt-H 106 Alt-F3 36 Alt-J 107 Alt-F4 37 Alt-K 108 Alt-F5 38 Alt-L 109 Alt-F6 - 42 - Appendix C: CLIPPER EVENT TRAPPING ---------------------------------- Using Clipper's SET KEY n TO procedure command in conjunction with any of COMET's event trapping commands may produce some undesirable side effects. The problem becomes evident when an ONDCD, ONDONE or ONTIME event occurs during a full screen READ operation. Clipper detects the keyboard character produced by the ONxxxx event and branches to the SET KEY procedure without a problem. However, upon RETURNing to the READ's active GET field, the cursor position always gets forced to the field's leftmost (home) position. The cursor would appear to suddenly jump every time an event occurred. It is recommended that the following code be put inside the SET KEY procedure to alleviate this problem. It takes advantage of the READVAR() parameter that is automatically passed to any SET KEY procedure. PROCEDURE WhatEver PARAMETERS Proc, Line, Var && Automatically passed * * Place desired event code here * * Cursor fix code IF LEN(Var) > 0 && Is a GET/READ in effect ? PosnInGet = LEN(&Var) && Determine position * Stuff right arr's to restore this position KEYBOARD REPLICATE(CHR(4), PosInGet) ENDIF RETURN && Exit SET KEY procedure - 43 -