Newport ESP300 RS232

[aopowers]

I've been trying for a few days now with no luck to control a Newport ESP300 motion controller with NI-VISA through RS232. It seems like it should be straightforward, but everytime I try, I get this:

Read Operation
Error

VISA: (Hex 0xBFFF0015) Timeout expired before operation completed.

This started with trying to use Python and pyVisa to control it, but I get the same error there. Am I missing something obvious? Any help is appreciated!

[Albert.Geven]

Which software did you use, is the cabling correct, etc.

A lot of possibilities not to mention is the power connected.

Give us a bit more info, to help you better.

[Gloorious_Leader]

Hi aopowers,

A timeout error often indicates that the Read Operation's termination requirements are not being met. Reads can be terminated after receiving a specified number of bytes or by receiving a specified termination character. I would check the ESP300 manual to determine which termination method you should be using.

It could also indicate that the ESP300 isn't responding at all to the serial commands you are sending it. You can try to use NI IO Trace to see if there is any data being returned by the read, even if it's timing out. You can also use a scope to probe the transmit wire to see if any signals are actually being sent. Again, use the ESP300's manual to determine the correct format of your serial commands to prompt a response from the instrument.

[aopowers]

Thanks for the quick replies! I didn't know what all information I should provide, but now that you have asked, I can give.

I'm trying to use VISA interactive control just to manually check it before I try writing programs for it. I'm positive the cabling is correct as its just RS232 from the controller to the pc. Of course the power is connnected.

According to the manual, read termination should be both newline and carriage return and the write term char is carriage return.  

[Albert.Geven]

Instead of developing all software yourself, search for drivers for this controller.

Not all have the same quality but better than bilding it yourself.

Be aware that not all serial cables are the same. two major series are the wire 1:1 and the null cable that switches e.g. read and write signals to each other to connect two of the same ports.

I'm not sure what you need but probably a 1:1 cable.

[aopowers]

I have been able to find a suitable driver. The protocol for communicating over serial seems pretty straightforward. 

I'm pretty sure I have the correct serial cable, but it doesn't list on the cable which type it is. Is there anyway to tell? Also the manual just says RS232, nothing more specific than that.