No response when query data from SA MS2665G via rs232c

[bunphotk]

I can send command to control Anritsu MS2665G spectrum analyzer via RS232C but I cannot read data from SA. The SA setting can be changed propery follow command I sent but when I tried to query data, there was no response. I'm using VB program. With the same program, I can read data from Agilent spectrum analzyer. I did a loop test with serial cable, it not a problem.

[Can_W]

Hi bunphotk,
The problem that you are describing can have several causes, hardware, software or a combination of both. Have you tried verifying that the signals are coming in. You can do this by using NI-SPY, found in Start->Programs->National Instruments->NI-SPY. Could you also try to example codes that come with NI-VISA, if that is the driver you are using to communicate. Once we get a little more detail we may be able to get to the root of the issue.