AnsweredAssumed Answered

Can't READ from E3633A

Question asked by mikesd on Feb 7, 2013
Latest reply on Mar 20, 2013 by kt
I have a bit of a strange problem with my E3633A Power Supply.  I don't seem to be able to get the Connect Expert to connect properly, to READ from the instrument.
My setup is: COM1, 9600, 8, none, 1 (verified on instrument and PC).  I have updated the instrument drivers for the PC.  I have the latest I/O drivers (16.3) and the VISA interface, from Agilent.
What I have found so far:
1) The first problem comes when I "Add Instrument" to my COM1 port.  After the instrument is found and added to the interface, it has a red X, instead of the green check mark.  The red X has an indication on the right that says, "There was a communication failure"
2) I notice is that the IDN string is blank in the connection expert, which suggests it couldn't be read from the instrument.

3) I noticed was that if I select the instrument (ASRL1::INSTR), the Interactive I/O option is grayed out.  However, if I create an alias, I can use that line to select the interactive I/O and send commands.
4) I have verified that I can send most commands to (Write) the instrument (i.e. *CLS, Volt 12, OUTP ON, etc).  Those seem to work.  One of the commands is self test, and when I Write that command, the instrument does a self test and displays PASS on the PS.
5) However, any of the Read commands (IDN?, etc) produce a timeout error, after 15+ seconds.  That error is: VI_ERROR_TMO: A timeout occurred.  I have also used the I/O Monitor to monitor the COM traffic and the only thing that appears not to work are the Read commands.
6) The Read timeouts don't produce an error on the Power Supply.  But I have found that multipe Writes will produce the "Error" on the PS.  For instance, if I execute *TST?, followed by another *TST?.  The second one will produce the Error, on the PS.  It still does the tests in both cases but the 2nd one will turn on the Error indicator.  Same for most Write commands.
7) I thought it might just be my cable but I tried another with the same results.  I also did a loopback by connecting TX to RX and verified that I am receiving through the cable and my serial card.  So the problem seems to be in the instrument.  Configuration?  I don't see any place to configure anything except the RS-232 and that's all correct.
Any idea what I may have forgotten or what might be wrong?