Controlling Mainframe Module with PyVisa

Hi,

I have a Stanford Research System SIM900 Mainframe and I can communicate with it using Pyvisa. Now, I would like to communicate with the PID module SIM960 connnected to it.

I can send commands such as : mainframe.ask("*IDN?"), etc...

My problem is that I cannot send command to the module.

For example to assign the module to the 4th mainframe port outside of python I would have to type : CONN 4,"PID"

and I could then type: PID*IDN?

to get the model of the module with the variable name PID.

In python I can only give one argument to mainframe and I cannot write something like : mainframe.write("CONN 4, "PID"") and mainframe.write("PID*IDN?")

To summarize, I want to send command from python to the PID module through the mainframe (COM5 for example)  but I don't know what's the syntax for it.

Does anyone ever experienced this situation?

Thanks

Vincent