Timeout error every other GPIB command

[morpheus77]

Hi,

I am sending periodically same GPIB command "*IDN?\n' to my instrument. I am talking via the GPIB interface. This works perfectly on the NI VISA test panel. If I ran it in my program I will get the first command response correctly, the second time will fail with timeout, the third will be fine and the fourth will fail and so on. I have checked and there is no loops in my GPIB setup.

I tried to slow down the periodic with longer interval but it did not help 

Any thoughts?

Thanks

C:\Windows\System32>python -m visa info
Machine Details:
Platform ID: Windows-7-6.1.7601-SP1
Processor: Intel64 Family 6 Model 60 Stepping 3, Genuine

Python:
Implementation: CPython
Executable: C:\Program Files (x86)\Python36-32\python.exe
Version: 3.6.1
Compiler: MSC v.1900 32 bit (Intel)
Bits: 32bit
Build: Mar 21 2017 17:54:52 (#v3.6.1:69c0db5)
Unicode: UCS4

PyVISA Version: 1.8

Backends:
ni:
Version: 1.8 (bundled with PyVISA)
#1: C:\Windows\system32\visa32.dll:
found by: auto
bitness: 32
Vendor: National Instruments
Impl. Version: 17825792
Spec. Version: 5244672
#2: C:\Windows\system32\visa32.dll:
found by: auto
bitness: 32
Vendor: National Instruments
Impl. Version: 17825792
Spec. Version: 5244672

[Machop]

Is there a posibility for you to attached your code? the python code. 

[Minions · Accepted solution]

Are you initializing the port, writing, reading, then closing the port or looping on the write and read section only?  Most devices do not react well to initializing/opening the port numerous times without closing it first. 

[morpheus77]

Thank you. The problem seems to go away after I upgraded the firmware version. 

[morpheus77]

I added time delay for before every query and after a close