Lake Shore 625, User Manual

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Lake Shore Model 625 Superconducting MPS User’s Manual
5-22 Computer Interface Operation
Table 5-6. Quick Basic IEEE-488 Interface Program
' IEEEEXAM.BAS EXAMPLE PROGRAM FOR IEEE-488 INTERFACE
'
'
This program works with QuickBasic 4.0/4.5 on an IBM PC or compatible.
'
'
The example requires a properly configured National Instruments GPIB-PC2 card. The REM
' $INCLUDE statement is necessary along with a correct path to the file QBDECL.BAS.
' CONFIG.SYS must call GPIB.COM created by IBCONF.EXE prior to running Basic. There must
' be QBIB.QBL library in the QuickBasic Directory and QuickBasic must start with a link
' to it. All instrument settings are assumed to be defaults: Address 12, Terminators
' <CR> <LF> and EOI active.
'
'
To use, type an instrument command or query at the prompt. The computer transmits to
' the instrument and displays any response. If no query is sent, the instrument responds
' to the last query received. Type "EXIT" to exit the program.
'
REM $INCLUDE: 'c:\gpib-pc\qbasic\qbdecl.bas' 'Link to IEEE calls
CLS 'Clear screen
PRINT "IEEE-488 COMMUNICATION PROGRAM"
PRINT
CALL IBFIND("dev12", DEV12%) 'Open communication at address 12
TERM$ = CHR$(13) + CHR$(10) 'Terminators are <CR><LF>
LOOP2: IN$ = SPACE$(2000)
'Clear for return string
LINE INPUT "ENTER COMMAND (or EXIT):"; CMD$ 'Get command from keyboard
CMD$ = UCASE$(CMD$) 'Change input to upper case
IF CMD$ = "EXIT" THEN END 'Get out on Exit
CMD$ = CMD$ + TERM$
CALL IBWRT(DEV12%, CMD$) 'Send command to instrument
CALL IBRD(DEV12%, IN$) 'Get data back each time
ENDTEST = INSTR(IN$, CHR$(13)) 'Test for returned string
IF ENDTEST > 0 THEN 'String is present if <CR> is seen
IN$ = MID$(IN$, 1, ENDTEST – 1) 'Strip off terminators
PRINT "RESPONSE:", IN$ 'Print return string
ELSE
PRINT "NO RESPONSE" 'No string present if timeout
END IF
GOTO LOOP2 'Get next command