Lake Shore Model 218 Temperature Monitor User’s Manual
6-6
Remote Operation
Table 6-1. Sample BASIC IEEE-488 Interface Program
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IEEEEXAM.BAS EXAMPLE PROGRAM FOR IEEE-488 INTERFACE
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This program works with QuickBasic 4.0/4.5 on an IBM PC or compatible.
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The example requires a properly configured National Instruments GPIB-PC2 card. The REM
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$INCLUDE statement is necessary along with a correct path to the file QBDECL.BAS.
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CONFIG.SYS must call GPIB.COM created by IBCONF.EXE prior to running Basic. There must
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be QBIB.QBL library in the QuickBasic Directory and QuickBasic must start with a link
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to it. All instrument settings are assumed to be defaults: Address 12, Terminators
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<CR> <LF> and EOI active.
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To use, type an instrument command or query at the prompt. The computer transmits to
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the instrument and displays any response. If no query is sent, the instrument responds
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to the last query received. Type "EXIT" to exit the program.
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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
