02-08-2014 05:22 AM
Hi,
I have a DC servo with 3-channel encoder and Maxon Epos P 24/5 controller, connected via RS232 to a Windows XP machine with Labview 2013.
Epos Studio 2.0 works fine, PIDs are tuned and all functions work 100%. When I try any of the Maxon example VI's, however, it gives me this "error reading USB data. (0x23000002)"
I can communicate with EPOS in Labview using NI VISA. I have recorded the sequence that Epos Studio sends when scanning COM interfaces (something with hex 07 00 00 00 ). I have sent this sequence via "write to COM port" VI, and received a response from EPOS P.
If I put my COM Tx and Rx lines on the oscilloscope and run the example VI, I see that at the execution of "VCS Set Operation Mode" VI the computer sends one byte to EPOS, but EPOS does not respond with anything. I guess the read times out and triggers the error. Other EPOS VI's which query the controller for information produce the same error, as EPOS does not talk back to them either...
I urgently need assistance on this matter. Thank you in advance for your prompt response!
02-09-2014 05:24 AM
I need to apologize for confusion. I wrote "error reading USB", while of course I mean "error reading RS232" everywhere in the text. Sorry for that, but the question remains - why do the Maxon LabView VIs give this error when communicating via COM port to EPOS P?