Closes a VISA connection to an Instrument/Device
#include <Visa.au3>
_viClose($h_session)
Parameters
| $h_session | A VISA session handle (as returned by _viOpen) |
Return Value
| Success: | Returns 0. |
| Failure: | Returns -1 if the VISA DLL could not be open or a NON ZERO value representing the VISA error code (see the VISA programmer's guide). |
Remarks
As for all the VISA functions the VISA libraries must be installed (you can check whether visa32.dll is in {WINDOWS}\system32) and a GPIB card (such as a National Instruments NI PCI-GPIB card or an Agilent 82350B PCI High-Performance GPIB card) must be installed
Related
_viClose, _viExecCommand
Example
;- This assumes that you have instrument set to GPIB address 1
; It shows how to use the _viExecCommand function in stand alone mode and combined
; with _viOpen and _viClose.
; It also shows the _viGTL function
#include <Visa.au3>
Dim $h_session = 0
; Query the ID of the instrument in GPIB address 3
MsgBox(0,"Step 1","Open the instrument connection with _viOpen")
Dim $h_instr = _viOpen("GPIB::3::0")
MsgBox(0,"Instrument Handle obtained", "$h_instr = " & $h_instr) ; Show the Session Handle
; Query the instrument
MsgBox(0,"Step 2","Query the instrument using the VISA instrument handle")
$s_answer = _viExecCommand($h_instr,"*IDN?") ; $h_instr is NOT A STRING now!
MsgBox(0,"GPIB QUERY result",$s_answer) ; Show the answer
; Query again. There is no need to OPEN the link again
MsgBox(0,"Step 3","Query again. There is no need to OPEN the link again")
$s_answer = _viExecCommand($h_instr,"*IDN?")
MsgBox(0,"GPIB QUERY result",$s_answer) ; Show the answer
MsgBox(0,"Step 4","Close the instrument connection using _viClose")
_viClose($h_instr) ; Close the instrument connection