Hi everyone,
sorry to post this kind of question again, but I've spent 2 days browsing this forum, the Mathworks forum, and several web pages, I still can't find the trick that will solve my problem :(
I am trying to control an Agilent 34970A (with the 34908A 40-channel module) to read temperature values from thermocouples. I am using a laptop (win7/64) and a USB-to-serial adapter (MCT U232-P9, which uses the Philips P87C52X2BA chipset, not the FTDI, in case it makes a difference) and I installed the driver for this adapter. The adapter is recognized by Windows and appears as COM4.
I set the COM port parameters in Windows as they are on the device (9600 Baud, Parity:none, 8 Data bits, Flow Control: Xon/Xoff; the stop bits are not specified on the device).
And... TADAAA... it doesn't work!
I tried using NI MAX (version 5.5), LabView (version 2013/32-bits), and MatLab (R2012b) to send the *IDN? command and read the answer. The "write" part goes ok (at least it doesn't generate an error, but I don't know if the command reaches the instrument), but there is no answer from the device. If I try reading from the COM port, I get the 1073807339 error (timeout before operation completed). I tried to look if there were any Bytes to be read at the port, but there are none...
In LabView, I set the Xon and Xoff characters to those specified in the Agilent manual (0x11 for Xon and 0x13 for Xoff), but there are a few other parameters I'm not so sure about: 'Enable Termination Char' (Should be On or Off? Tried both - no change) and the termination char itself (I left it to the default '\n').
I know this is not really an NI/Labview issue, but since so many people in this community seem to have experienced this problem, I would be very grateful if anyone can help me solve this!
Thanks in advance
Mathieu