Traceback (most recent call last): File "./test_gpib_prologix.py", line 118, in <module> result0 = f.get("LAST? %d" % chan) File "./test_gpib_prologix.py", line 83, in get self.checkErr(cmd) File "./test_gpib_prologix.py", line 67, in checkErr raise IOError('Error for command string [' + cmd + "]:\nError " + repr(error) + ': ' + esrStatusBits.get(error, repr(error))) IOError: Error for command string [LAST? 0]: Error 4: Query error