2635A
Users Manual
4-10
One of the following three possible prompts are returned when a command is sent to
the instrument:
=> The command was executed [Example, PRINT 1].
!> The command was recognized, but not executed [Example, PRINT 3,
where only PRINT 0 and PRINT 1 are legal entries].
?> The command wasn’t recognized [Example, PRITN 1, spelling error].
4. Other commands can be entered from the PC to gain familiarity with the instrument
command set. All commands are summarized in Table 4-4 and explained in Table 4-
5. For example: to reset the instrument, configure channel 0 to measure volts dc
using the 300V DC scale (scale 4), send scan results to the RS-232 port, and scan
once, enter the following [only the output of the last command is shown]:
PRINT #1, "*RST":PRINT INPUT$(10, #1)
PRINT #1, "FUNC 0, VDC,4":PRINT INPUT$(18, #1)
PRINT #1, "PRINT_TYPE 0,0":PRINT INPUT$(20, #1)
PRINT #1, "PRINT 1":PRINT INPUT$(13, #1)
PRINT #1, "*TRG":PRINT INPUT$(83, #1)
15:17:0407/21/94
0:000.00 VDC
ALM:15DIO:255TOTAL:0
To decode the printout, see Figure 5-3.
The commands in the above example can be combined into a single entry by using
the semicolon separator character:
PRINT #1, "*RST;FUNC 0,VDC,4;PRINT_TYPE 0,0;PRINT 1;*TRG":PRINT
INPUT$(124, #1)
If other commands are entered, remember that the input character count xxx for
PRINT INPUT$(xxx, #1) command must be exact. A number too small will not read
all the characters and will leave residual characters in the buffer, while a number too
big will "hang up" the command until more characters are loaded into the buffer or
<CNTL><BREAK> is pressed, which erases the buffer.
5. Enter SYSTEM to exit GWBASIC and return to DOS.
Testing the RS-232 Interface Using Qbasic
Complete the procedure below to test the RS-232 link between the PC and instrument
using QBASIC compiler commands. Identify the PC COM port used for the RS-232 link
(COM1 is assumed).
1. Configure the Data Bucket communication parameters, as described in Figure 4-2,
for bAUd = 9600, PAR = no, CtS = OFF, and Echo = On.
2. Turn on the PC and enter QBASIC to start the BASIC compiler.
3. With the entry screen displayed, enter the following commands (which are not
executed immediately):
OPEN "COM1,9600,N,8,1,CS,CD" FOR RANDOM AS #1
PRINT #1, "*IDN?"