1

I am making use of Prologix GPIB-USB Controller to be used in LISTEN ONLY mode (Device Mode) to decipher data communication between Two instruments namely Tester & Prober. I have written a sample program in python using Pyserial Module for this purpose.

The issue am facing is that i am able to see the Command and Response communicated between instruments , but cannot listen to the SRQ Signal send over GPIB bus. I am totally new to this area of GPIB programming and have very little knowledge about related stuff.

import os.path
import serial
import sys
from time import sleep

comport = '/dev/ttyUSB0'
# addr = '5'
ser = serial.Serial()

try:
    ser = serial.Serial( comport, 9600, timeout=0.5 )

    # Switch to DEVICE mode
    cmd = '++mode 0'
    print('Sending:', cmd)
    cmd = cmd + '\n'
    ser.write(cmd.encode('UTF-8'))

    # Set instrument to LISTEN ONLY mode
    cmd = '++lon 1'
    print('Sending:', cmd)
    cmd = cmd + '\n'
    ser.write(cmd.encode('UTF-8'))

     # Read the Data from GPIB BUS
    while(True):
        s = ser.read();
        if len(s) > 0:
            print(s)

except(serial.SerialException, e):
    print(e)
    f.close()

except(KeyboardInterrupt, e):
    ser.close()
    f.close()

I am running this code from a Raspberry Pi connected to one end of GPIB-USB Controller and other half connected to GPIB BUS (Connected to both Tester and Prober).

I am able to see all the commands transmitted from Tester and also response for those commands from Prober , But for certain commands the Prober reply back with a SRQ Code , But that is not visible in the Data output collected by this setup.

Output Collected:

F
PN0
?V
PN00453             ,Rzz00-R014.08R,P12,0000000000000000
a
020020
f1
000.0
G
COTBIRD-5S-2CPB-NL  
T (Missing SRQ Reply for this Command)
O
A
A
019021

I am very sure that the SRQ Code is sent after command "T" as i can see the same in Prober Data log generated.

Any guidance would be helpful

1 Answer 1

0

The issue was solved by issuing the ++spoll command which reads out the Serial Poll SRQ value requested from the device.

1
  • Please accept your own answer with a click on the tick on its left side. Only this will finish the question and it will not pop up again year for year.
    – Ingo
    Dec 26, 2019 at 14:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.