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.
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