Programmer 7500

home *** CD-ROM | disk | FTP | other *** search

/ Programmer 7500 / MAX_PROGRAMMERS.iso / PROGRAMS / UTILS / HAMRADIO / CABLPOWR.ZIP / HELP.TXT next >

Wrap

Text File | 1990-05-07 | 37.0 KB | 830 lines

╔═════════════════════════════════════════════════════════════════════╗ ║ The Powering Program ║ ╚═════════════════════════════════════════════════════════════════════╝ (C) 1987 by Frank A. Himsl c/o LanStart Inc. 504 Iroquois Shore Road Oakville, Ontario CANADA L6H 3K4 Telephone: (416) 842-2780 Facsimile: (416) 842-5635 The Powering Program is a design tool for the broadband network designer. You can do fast and accurate calculations of voltages and current consumptions for systems of broadband amplifiers of any complexity or size for both cable television systems and Local Area Networks (LAN's). Accuracy is ensured by an iterative recursion technique and data structures simulating the real-world tree configuration of broadband networks. You can get significant power and capital savings by minimizing the number of power supplies and optimizing their placement in the broadband network. Because the required manual calculations are tedious, repetitive and time-consuming, many broadband designers generate conservative, inefficient power designs in the interest of saving time. The Powering Program can eliminate this kind of inefficiency. ╔═════════════════════════════════════════════════════════════════════╗ ║ Background ║ ╚═════════════════════════════════════════════════════════════════════╝ Most systems of broadband CATV-style (Community Antenna TeleVision or Cable TV) amplifiers are cable-powered. Step-down transformers (sometimes equipped with stand-by batteries) are located throughout the broadband network of cables and amplifiers. These transformers impress 60 volts of alternating current (and sometimes 30 volts) onto the cable. Each amplifier has its own power pack as part of its basic circuit. This power pack will accept an input voltage anywhere from about 30 volts AC to 60 volts AC. This input is stepped down, rectified and filtered to supply a constant, clean, ripple-free, 24 volts (usually) of direct current (DC) to the transistorized circuitry of the broadband amplifier. (Note: The power pack is often referred to as the 'power supply'. To eliminate possible confusion, in this document, 'power supply' refers to the pole or pedestal mounted transformer impressing the alternating current on the cable, and the term 'power pack' describes the circuit in the amplifier used to step-down, rectify and regulate the input voltage to the amplifier.) There are two basic types of circuits used in power packs: 1) Switching regulated circuits and, 2) Series regulated circuits ╔═════════════════════════════════════════════════════════════════════╗ ║ Switching Regulated Power Packs ║ ╚═════════════════════════════════════════════════════════════════════╝ These power packs utilize a transistor switch and capacitors to tap off energy from the cable on a demand basis. When the voltage supplied to the circuit is high, the transistor switch closes for only short periods of time, allowing current to briefly flow into the storage capacitors. When the input voltage is lower, the switch stays closed for longer periods of time, allowing the capacitors sufficient time to become fully charged. The voltage regulator converts and stores excess energy for useful output to the amplifier circuit. This approach is efficient (6-10% better than series regulation) and minimizes the power consumption of the amplifier. They are also called 'Constant Power Supplies' since the power drain is reasonably constant over a wide range of input voltages. ╔═════════════════════════════════════════════════════════════════════╗ ║ Series Regulated Power Packs ║ ╚═════════════════════════════════════════════════════════════════════╝ In this type of power pack, voltage in excess of that required by the amplifier is dropped through a resistor and is converted (wasted) to heat. Generally, this type of circuit will draw a constant current, independent of the input voltage. To minimize the wasted energy, the step-down transformer is often provided with taps, each marked with a range of input voltage ranges. (With type of power pack, it is recommended that you enter the amplifier/node consumption as a constant power, instead of constant current. This is due to the current flow, as a function of input voltage, more closely approximating that of the switching circuit) The Powering Program can handle both types. ╔═════════════════════════════════════════════════════════════════════╗ ║ The Basic Approach ║ ╚═════════════════════════════════════════════════════════════════════╝ Before entering any data, take your design sketch or map showing the network of cables and amplifiers and assign a unique number to each amplifier, splitter, power inserter and directional coupler in the area which you are going to work. These locations are generally called 'nodes'. No number may be less than 0 (zero) or larger than 9999. The network of cables and amplifiers can be as complex or as simple as you wish. Data are entered into the program as individual cables running between amplifiers and/or passive devices such as taps, splitters, power inserters and directional couplers. These cables may be in any random order. ╔════════════╗ ╔════════════╗ ║ Node 1 ║------------------------------║ Node 2 ║ ╚════════════╝ Cable ╚════════════╝ As you key in the data to the computer, it is recommended that you take a colored pen or pencil and mark off the cables as they are entered. This will help you to monitor your progress and avoid duplicate entries. The power (or current) consumption of each amplifier is automatically assigned based on the typical device being installed with that kind of cable. You can modify individual nodes after a batch of cables has been added. (See the 'Print Splits' command). You can: - Edit cable lengths - Edit cable specifications - Edit amplifier or node data - Remove cables - Add cables - Save and Read data and specifications from disk - Globally 'search and replace' voltages or currents A location for a power supply is then selected and entered; the computer will build an internal 'tree' and then accurately calculate the voltage and current at each node. An important feature is the capability to finely tune or design the powering layout. In this way, an optimal layout can be configured. To do this, tools are provided that enable you to: - Choose any point as a power supply and recalculate results - 'Block' any cable, thereby allowing multiple power supplies within the data. - Delete or Move blocks - Try out all points within a layout as potential power supply locations, quickly determining the most efficient location. Allowing for the future ----------------------- If you plan to expand the functionality of your amplifiers in the future by adding such items as status monitoring, two-way, bridger switching, or feed-forward amplification, you should allow for these as well by increasing the current or power consumption. ╔═════════════════════════════════════════════════════════════════════╗ ║ Detailed Operation of the Program ║ ╚═════════════════════════════════════════════════════════════════════╝ Running the Program ------------------- Before you start, please make a -={ BACK UP COPY }=- of the program distribution disk. If you have worked with computers for even a short while, you will realize that although diskettes are quite rugged and we all promise ourselves to be careful all the time, accidents do happen! On top of that, a computer glitch can wipe out an important program or valuable data in a millisecond. Check the DOS manual for documentation on the DISKCOPY and COPY commands. If you have a hard disk drive for your machine, you may copy the files onto it for more convenient operation. When run for the first time, you may get an error message indicating that a file has not been found. Don't panic! This is merely indicating that the default specification file RESISTAN.CES has not been found. By executing the Specifications command, you can enter your own specifications; when complete, save the information in a file called RESISTAN.CES. Each time the program starts up, it will then read this data. You may also save different specifications under other file names. ╔═════════════════════════════════════════════════════════════════════╗ ║ Main Menu ║ ╚═════════════════════════════════════════════════════════════════════╝ After you enter the command POWER, a meu will appear: C: Compute Voltages, Currents | Bytes free: 430624 O: Optimize Voltage | P: Print Cables, Nodes, Voltages, Blocks | P/S Voltage: 60.00 A: Add Cables | M: Modify Cables, Nodes | D: Delete Cables | B: Block Cables | U: Un-Block Cables | K: Kill All Cables | # of Cables: 0 R: Read All Cables from disk | # of Blocks: 0 W: Write All Cables to disk ------------------------------ F: Files Disk Directory S: Specify Cables; Save Specs H: Help ({Enter}: Command Menu) >: Sort Cables Q: Quit V: Voltages to screen Also, a briefer menu will appear at the bottom of the screen: Command? Add Modify Block Compute Read Specs Print Quit > Kill Delete Unblock Optimize Write Files Volts Help ? (This brief menu will always appear when no command is being executed, whereas the full-screen menu will appear only if you press the the {Space} bar or the {Enter} key at the Command? prompt.) To use any of the commands listed, merely press the first letter of the command desired. All keystrokes are converted to upper case when entered, so it does not matter whether you enter A or a if you wish to add cables. ╔═════════════════════════════════════════════════════════════════════╗ ║ Entering cable span data ║ ╚═════════════════════════════════════════════════════════════════════╝ Data are entered into the computer in two stages: cable entry and modifying nodes. At the main command level, choose the A command to 'Add' cables to memory. A display will appear: (1) (2) (3) (4) | | | | | | | | v v v v Input: Span Length 0 From 1 To 2 Cable 7 (Press: < > 0 1 2 3 4 5 6 7 8 9 0 L F T C Q {Enter}) (Bytes free= 410352) At the top of the screen, two boxes connected by a line will appear. The boxes represent nodes or amplifiers and the line represents the cable interconnecting the two nodes. At this point the computer is awaiting entry of these items: 1) The length of cable interconnecting the two nodes, 2) & 3) Numbers (which you must assign) of each node. These numbers must be unique i.e. you may not assign more than one number to a node. 4) The code representing the type of cable running between the nodes. You do not need to enter the power or current consumption of each node╗ this is automatically assigned based on the default values you have originally selected for each cable type. Wait until you have entered all of your data before attempting to Modify or edit the values automatically assigned by computer. (See the 'Print Splits' command). The keys that you may press are listed on the bottom line of the screen. Type the number keys (0, 1, 2, 3, 4, 5, 6, 7, 8 and 9) to enter cable lengths and node numbers. Decimals are not permitted in node numbers or cable distances. The left <- and right -> arrow keys may be pressed to move the cursor back and forth between fields. You may press {L} (Length), {F} (From), {T} (To) or {C} (Code) to explicitly jump to these fields. Pressing {Q} when the cursor is located in the Length, From or To fields will allow you to exit the data entry mode. When the cursor is located in the Cable Code field, you may press only the {Enter} key, a valid cable code (that you have previously assigned) or the Left or Right arrow keys. (For Wordstar fans, {CTRL S} or {CTRL D} may be pressed instead of the arrow keys to move Left and Right.) When the {Enter} key is pressed while in the Length or Cable Code fields, the data displayed on the screen will be accepted. The computer will display the new information at the top of the screen, create new nodes as necessary and assign the default current and/or power consumptions. You may then continue with further cables or issue the {Q} (Quit) command. If you discover an error in a cable previously entered, you may either exit the data entry mode and Delete or Modify the information, or you can wait until after all the data are entered before making your corrections. Default Node Consumption ------------------------ As cables are entered, pre-selected power or current consumptions are automatically assigned to each new node. For example, as you enter lengths of 3/4" (0.750") cable, each new node might be assigned a consumption of 38.5 watts; when 1/2" cable is being entered, the program might begin to assign 0.44 amperes to each node. When all cables are entered, you can then Modify Nodes Individually where the default value is not correct. (This is necessary for each splitter, directional coupler, splice, tap or power inserter.) This approach greatly simplifies and speeds up the data entry process. Use the 'Print Nodes' command to view all nodes and the 'Print Splits' command to show only those nodes where more than two cables meet. If you enter a duplicate cable or are about to create a loop (instead of the usual tree), the computer will issue an appropriate message. ╔═════════════════════════════════════════════════════════════════════╗ ║ Modifying Data ║ ╚═════════════════════════════════════════════════════════════════════╝ Command Summary: Modify - Cables - Nodes - Individually - Globally - Watts - Amps To modify data (cable spans or node information), use the {M} (Modify) command. You will be prompted to select {C} for Cables, {N} for nodes or {Q} to Quit. Modifying Cables ---------------- To modify the length or cable code for a specific cable span, press the {C} (for Cables) key. The computer will prompt you to enter the node numbers at each end of the cable, then to enter the new cable length and new cable code. To exit the Modify Cables mode, enter {Q}. Modifying Nodes --------------- To modify the power or current consumption at any existing node, press the {N} (for Nodes) key. The computer will then prompt you to enter {G} for Globally or {I} for Individually. Modifying Individual Nodes -------------------------- To Modify Individual Nodes, press the {I} (for Individual) key. The computer will then prompt you to enter the node number, new constant power and new constant current for the node number selected. To exit, enter {Q} as a node number. Modifying Globally ------------------ If you have entered a large number of nodes with a default constant power of say 27 watts and you wish to change this to 27.95 watts, you can use the Modify Globally command. Enter {G} when prompted to select 'Globally' or 'Individually'. The computer will then prompt you to select Watts or Amps. To globally change Watts, press {W}. The computer will then prompt you to enter the value to be changed. Enter 27 watts and then press the {Enter} key. Next, the computer will prompt you to enter the new value. Enter 27.95 and press the {Enter} key; the computer will search for all nodes with a constant power consumption of 27 watts. Each such node will be changed and the node number, old value and new value will be displayed on the screen. ╔═════════════════════════════════════════════════════════════════════╗ ║ Deleting Cables ║ ╚═════════════════════════════════════════════════════════════════════╝ To delete a single span or length of cable, select the {D} Delete command. The computer will prompt you for the node numbers at each end of the undesired cable. When both are entered, the list of cables will be searched and if found, the undesired segment of cable will be deleted. ╔═════════════════════════════════════════════════════════════════════╗ ║ Sorting Cables ║ ╚═════════════════════════════════════════════════════════════════════╝ If you enter cables at several different times, the listing you get with the 'Print' 'Cables' command will be shown in chronological order, possibly making it difficult to find a desired section of cable. To sort the cables into ascending order, press the {>} ('greater than') key at the main Command? prompt. If you respond with {Y} to the 'Are you sure? Y/N' prompt, the cables will be sorted. From To From To 8 7 1 2 Original: 3 2 Sorted: 2 3 999 7 7 8 1 2 7 999 ╔═════════════════════════════════════════════════════════════════════╗ ║ Killing or deleting all cables ║ ╚═════════════════════════════════════════════════════════════════════╝ Before you enter new data or you want to read in new data from the disk, you may wish to 'Kill' any existing information in the computer's memory. To do so, select the {K} (Kill) Command. If the information has not been stored on disk, you will be cautioned and be given the opportunity to abort the Kill Command. ╔═════════════════════════════════════════════════════════════════════╗ ║ Calculating Voltages ║ ╚═════════════════════════════════════════════════════════════════════╝ To see the result of placing a power supply at a particular node, press {C} to 'Compute' (or {G} to 'Go'). The computer will prompt you for a power supply location. Enter the node number of the tentative power supply and press {Enter}. The computer will quickly build an internal data structure (known in computer science as a binary tree) and then iteratively calculate voltages and currents. This process usually takes just a few seconds. When processing is complete, the results are displayed on the screen. The Power Supply location, the node with the lowest voltage and the total current are displayed as well. ╔═════════════════════════════════════════════════════════════════════╗ ║ Placing power blocks ║ ╚═════════════════════════════════════════════════════════════════════╝ A power block is simply a section of cable which the computer must skip when building its internal data structure for voltage calculations. All nodes 'downstream' of the block will be ignored unless there is an alternative path to them. By placing or deleting blocks, you can tailor or customize the power layout for optimum efficiency. To place a block, select the {B} (Block) Command; enter the node numbers on each end of the desired cable. When cables are displayed, the Blocks will be clearly shown. When designing large groups of amplifiers such as in a large sub- division or small town, ALL of the nodes and tentative power supplies may be entered into the computer. Merely by placing strategic blocks, you can calculate the voltages for each group of amplifiers fed by specific power supplies. This also allows you the freedom to play around by moving blocks and power supplies around, optimizing and tuning the power layout. ╔═════════════════════════════════════════════════════════════════════╗ ║ Un-Blocking or removing power blocks ║ ╚═════════════════════════════════════════════════════════════════════╝ To remove a block (or all blocks), use the {U} (Un-block) Command. A short menu will appear: Unblock Cables: All Individually Quit To Un-block cables one-by-one, press {I} (for Individually). The computer will ask you for the cable segments and un-block them. Press {Q} when you are done. To un-block all cables, press {A} (for All). The computer will double- check that you want to do this and then perform the command. ╔═════════════════════════════════════════════════════════════════════╗ ║ Checking the results ║ ╚═════════════════════════════════════════════════════════════════════╝ If lengths of cable are excessively long or current consumptions are too high, or too many amplifiers are being fed, the network of cables and amplifiers may be impossible to power; this fact will be displayed when this happens. If so, try selecting a new power supply in a more central location or try block off cables to reduce the number of amplifiers being powered. It is your responsibility to examine the results and determine the feasibility of a given design. Things to watch for are: - Excessively low voltages ------------------------ When an amplifier is designed for a nominal input of 60 volts, it may not operate properly with input voltages less than 35 to 40 volts or so. Check with the manufacturer's specifications to be sure. - Excessively high current consumptions ------------------------------------- Most CATV power supplies are incapable of delivering more than 10 or 15 amperes of current. Again, check with the specifications. - Excessively high current flow on cables --------------------------------------- Certain equipment may be incapable of passing more than say 5 to 6 amperes without blowing fuses or creating excessive amounts of hum modulation distortion. Generally, try to avoid more than 7 amps on any one section of cable. - Voltage instability ------------------- Occasionally, the lowest voltage found in the system may marginal or barely acceptable. If an amplifier is situated at the end of a long stretch of cable (which will have varying resistance according to the ambient temperature), or if the power pack in the amplifier is prone to vary slightly in its power consumption, the network may be unstable. Very small increases in cable resistance or power consumption can throw such a network into failure mode. (Try to avoid these unstable networks. Move power supplies or blocks to get higher terminal voltages. Another method to avoid instability is to enter power consumptions for your amplifiers slightly greater than specifications indicate, giving you some margin or breathing room.) ╔═════════════════════════════════════════════════════════════════════╗ ║ Optimizing the power layout ║ ╚═════════════════════════════════════════════════════════════════════╝ Depending upon the number, length and type of cables entered and the blocks placed, you may require one or more power supplies to power all nodes. If you have flexibility in selecting potential power supply locations, you may wish to quickly determine the most efficient location. To do this, use the {O} (Optimize) Command. The computer will prompt you for a starting point. Enter any one of the nodes in a particular area; the computer will then try to place a power supply at every node in that area. When complete, the computer will show you the best location to use. (Sometimes, this will not be possible if the area being powered is too large.) Please note: during the optimization process, no blocks are moved, added or deleted. After optimization is done, Compute the voltages using the 'best' location displayed. If the current consumption at the power supply is not excessive and the lowest voltage is greater than the manufacturer's specification, you may consider moving a block to permit more amplifiers to be serviced. After moving a block or two, Optimize again to see if the power supply location is still the best one. The process of interactively checking and moving various locations for power supplies and blocks can be performed quickly and raises your confidence level when you arrive at the final design. ╔═════════════════════════════════════════════════════════════════════╗ ║ Printing data ║ ╚═════════════════════════════════════════════════════════════════════╝ To view cable span data, issue the {P} 'Print' command. A brief menu will be displayed: Print: Hardcopy Cables Nodes Splits Voltages Blocks Quit Print Cables: ------------ To print cables, press {C}. The following display will appear: ({Enter} = All) Attached to Node # If you wish to see all of the cables in memory, simply press the {Enter} key. To see cables attached to a particular node only, enter the number of the desired node. Print Nodes: ----------- To print node information, press {N}. The node numbers, constant current and constant power consumptions will be displayed. Print Splits: ------------ To print out all nodes where more than two cables meet at a common spot, press {S}. The computer will print all of the splits in a format similar to the 'Print Nodes' command. Use this command after you have entered all your cables, since you can rapidly find the nodes which should have no power or current consumptions. Print Voltages: -------------- To print voltages calculated previously, press {V}. The node numbers, calculated voltages and currents will be displayed. As well, the Power Supply location and the node with the lowest voltage will be flagged. This command may also be executed from the main menu by merely pressing {V} for volts --- the 'Print' command does not need to be executed first. (It is important that you monitor the voltages and currents carefully, since the computer will not warn you if the voltage at an amplifier is lower than that recommended by the manufacturer. This is no different than a car manufacturer selling you a car with a 300 horsepower motor; how fast you go is entirely up to you!) Print Blocks ------------ To print the blocked cables, press {B}. As in the Print Cables command, you may select all blocked cables by pressing the {Enter} key, or only those attached to a specific node by entering its assigned number and pressing {Enter}. Print Hardcopy -------------- To obtain a hard copy of any of the above items (cables, nodes, voltages or blocks), press {H}. The computer will display the following message on the bottom line: 'Hardcopy Output now Enabled' and the prompt will change to include two extra choices: Print: Hardcopy Cables Nodes Splits Voltages Blocks Linefeed Pagefeed Quit -------- -------- If {L} is pressed, the printer paper will be advanced one line. If {P} is pressed, the printer paper will be advanced one page. Then, if the first letter of one of the other valid choices is pressed, the computer will send the appropriate report to the printer. ╔═════════════════════════════════════════════════════════════════════╗ ║ Saving cables to disk ║ ╚═════════════════════════════════════════════════════════════════════╝ To save your cable span data, select the {W} (Write) Command; enter the name of the file to be created. You may precede the name of the file with a sub-directory or drive designator. (It is suggested that you choose a file suffix such as .DTA or .CBL to remind you in the future of the file type.) The following are valid entries: A:test area100.dta \power\newspans ╔═════════════════════════════════════════════════════════════════════╗ ║ Loading cables from disk ║ ╚═════════════════════════════════════════════════════════════════════╝ To retrieve cables previously written or saved to disk, select the {R} (Read) Command and enter the name of the file to be read. As above, you may precede the name of the file with a sub-directory or drive designator. If you already have data in memory, the computer will issue a warning and ask if you wish to append the new data to the existing information. Exercise care if you choose to append the data, since if there are overlapping node numbers, the data may become scrambled. ╔═════════════════════════════════════════════════════════════════════╗ ║ Help ║ ╚═════════════════════════════════════════════════════════════════════╝ To display these help screens, press {H} or {?} for Help. A file called HELP.TXT will be read from the default directory. You can then use the arrow keys, {PgUp}, {PgDn}, {Home} and {End} to navigate through the screens. To get help on a specific item, press {F} (for Find) and key in a short sequence such as 'Blocks' followed by the {Enter} key. The computer will locate the first occurence of the word and print a new screen with the first line containing the requested data. (Case is not important; the computer will find 'Block' or 'BLOCK'). To find the next occurence of the same word, press {F} followed immediately by {Enter}. If the item is not found, a click will be heard and the first page of the help screens will be re-shown. Press {Esc} to Exit the help screens. (For Wordstar or Sidekick users: to navigate through the help screens, you also may use the control key sequences: ^E ^X ^R ^C ^QR ^QC). ╔═════════════════════════════════════════════════════════════════════╗ ║ Quit ║ ╚═════════════════════════════════════════════════════════════════════╝ To exit the program, select the {Q} command. If you have entered or modified cables or blocks and have not saved the cables by selecting the 'Write' command, the computer will beep and warn you. If you wish to quit, press, {Y}; otherwise, you will be returned to the main menu, at which time you may wish to save your data to disk. ╔═════════════════════════════════════════════════════════════════════╗ ║ Specify cables ║ ╚═════════════════════════════════════════════════════════════════════╝ In order to properly calculate voltage drops along lengths of cables, the computer must be given the loop resistance of the cables you are using. To specify these, select the {S} (Specify) Command. At the top of the screen, a listing of the current cable specifications and the default power and current consumptions will appear and a two- line menu will appear at the bottom of the screen: Specifications: Add Delete Modify Save Load Quit The 'Add', 'Delete' and 'Modify' commands enable you to create a list of the cable specifications for your broadband network. When complete, save your list to disk with the 'Save' command. You will be prompted to enter a file name. When you enter a name and press {Enter}, the data will be saved to disk. You may also read an existing specification file on disk by issuing the 'Load' command. You will be prompted to enter a valid filename. If the file exists, the data will be read and stored as a new cable specification list; otherwise, an error message will be shown. Default Specifications ---------------------- When the Powering Program first starts up, it searches the default directory for a specification file with the name: RESISTAN.CES If found, it will load the specifications stored in this file; otherwise, an error message is displayed. If you wish to have the program start up with the same specifications all of the time, save your cable list with this name (RESISTAN.CES). The following section describes each of the fields that are stored in the file. (See Appendix A for a discussion on the file format.) Cable code ---------- The computer will prompt you to enter a single letter or number by which the cable will be identified. Examples are {7} for 0.750" (3/4") cable and {5} for 0.500" (1/2") cable. Description ----------- This is a short (8 characters maximum) string of characters and/or numbers to describe the cable. Examples are: T4+500 or P3750B. Loop Resistance --------------- This is the resistance per unit distance of the cable type. Please note that you must enter the resistance per foot (or meter, if all of your lengths will be metric). For example, if your cable has a resistance of 0.77 ohms per 1,000 feet, enter: 0.00077 (ohms per foot). The loop resistance of a length of cable is the sum of the resistance of the outer conductor and the center conductor. (There are two basic types of center conductors: solid copper and copper-plated aluminum. Solid copper has the lower resistance but tends to cost significantly more) Default Power ------------- In order to speed up the data entry process, the computer automatically assigns a default power and default current consumption for each node that is created as the cables are entered. For example, if you will be using trunk amplifiers with a power consumption of 33 watts on your 3/4" cable, enter 33 watts as the default power. After all of cable cables are entered, you need only Modify those Nodes where the power or current consumption is not the default value. (See the 'Print Splits' command). Default Current --------------- As above, enter the default current consumption (measured in amperes, NOT mA NOR milliamperes) to be assigned automatically as nodes are created during cable entry. Example: 0.250 amps (250 mA or milliAmperes) Note: Generally, you will have EITHER a default power OR a default current, NOT BOTH. If your amplifiers have transformers with selectable taps for different voltage ranges, you may wish to enter the power consumption instead of the current consumption, since this type of power pack approximates the current consumption characteristics of a switching mode power supply. ╔═════════════════════════════════════════════════════════════════════╗ ║ Files ║ ╚═════════════════════════════════════════════════════════════════════╝ To see a directory of the files on disk, issue the {F} (Files) Command. You will be prompted to enter a 'Mask'. For the default drive, simply press the {Enter} key. As in DOS commands, you may also use wildcards: Valid examples: C: A:*.* B:*.pwr Please refer to your Disk Operating System manual for a discussion of masks and file naming conventions. Powering Program Files ---------------------- There are two types of files that the Powering Program will read and write: Cable files: contain cable lengths, cable codes and node numbers Specification files: contain cable codes, cable descriptions, default power, default current and loop resistances To distinguish between the two, it is recommended that you choose a suffix for your file names to remind you of the file type. Examples: Cable files: AREA1.CBL PHASE9.CBL Specification files: COMSCOPE.SPC JERROLD.AMP ********************** End of HELP.TXT file ************************