Omega Model CYD211 User’s Manual
Remote Operation
4-11
Table 4-4. Quick Basic Serial Interface Program
CLS
'Clear
screen
PRINT " SERIAL COMMUNICATION PROGRAM"
PRINT
TIMEOUT = 2000
'Read timeout (may need more)
BAUD$ = "9600"
TERM$ = CHR$(13) + CHR$(10)
'Terminators are <CR><LF>
OPEN "COM1:" + BAUD$ + ",O,7,1,RS" FOR RANDOM AS #1 LEN = 256
LOOP1: LINE INPUT "ENTER COMMAND (or EXIT):"; CMD$
'Get command from keyboard
CMD$ = UCASE$(CMD$)
'Change input to upper case
IF CMD$ = "EXIT" THEN CLOSE #1: END
'Get out on Exit
CMD$ = CMD$ + TERM$
PRINT #1, CMD$;
'Send command to instrument
IF INSTR(CMD$, "?") <> 0 THEN
'Test for query
RS$ = ""
'If query, read response
N = 0
'Clr return string and count
WHILE (N < TIMEOUT) AND (INSTR(RS$, TERM$) = 0)
'Wait for response
IN$ = INPUT$(LOC(1), #1)
'Get one character at a time
IF IN$ = "" THEN N = N + 1 ELSE N = 0
'Add 1 to timeout if no chr
RS$ = RS$ + IN$
'Add next chr to string
WEND
'Get chrs until terminators
IF RS$ <> "" THEN
'See if return string is empty
RS$ = MID$(RS$, 1, (INSTR(RS$, TERM$) - 1))
'Strip off terminators
PRINT "RESPONSE:"; RS$
'Print response to query
ELSE
PRINT "NO RESPONSE"
'No response to query
END
IF
END IF
'Get next command
GOTO
LOOP1
