LabVIEW VISA Test Panel unable to communicate with Chroma ATE 61504

Hello,

I meet some problems using VISA Test Panel in NI MAX to communicate with Chroma ATE 61504 AC source. 

I am using RS-232C serial port and I configured the port setting in NI MAX exact the same as the one in Chroma 61504.

Then I opened the VISA Test Panel and want to query its model information. However, VISA time out error occurs. I tried to query other information but the same error occurs.

I guess the communication does not seem to be established. But the display of the Chroma 61504 indicates that it is working in remote state. This makes me confused.

Could anyone please provide any comments or suggestions? Thanks.