Control HP34401 Via serial RS232 port (VB6)

[djklocek]

Hello.

I'm trying to control HP34401 via serial port using Microsoft Comm Control 6.0 Component (Visual Basic 6.0). Until now I'm not getting any answers from multimeter but errors (sometimes) but most of the time it's just no reaction.

For example:

MsComm1.PortOpen = True

MsComm1.Output = "SYST:REM" (from now on it should be REMote controlled)

I think I configured everything properly, same baud,parity,start/stop bits etc. The cables are ok.

I don't know what to do to make it work. I wrote a software to control it via GP-IB and everything was working fine but wit' this RS232 it doesn't look as simple.

Could anybody help me?

Thank you and best regards

[Dennis_Knutson]

In the command you're sending, I don't see any termination character. I don't know offhand what it supposed to be. It's a CR,LF, or both. Your programming manual should say.

[Makoto]

As my experience on controlling 34401A with RS232, the instrument requires a hardware flow control using DTR/DSR cross connection.  If your serial cable (probably a null-modem cable) does not cross-link DTR and DSR each other, the cable may not work.  (If the cable's connection housings have DTR/DSR self-terminate connection instead of true cross-link, the cable may work but no synchronisation will be graranteed.)  At least 34401A's DSR input signal (pin #6 in a 9-pin D-SUB connector) must be pulled up to HIGH in order that the instrument accepts any in-coming messages.  It is normally pulled up by the host side's DTR line if the cable is right.

Plus, your software driver (MSCOMM in your case) must enable DTR/DSR hardware handshake.

[djklocek]

Thanks Guys.

I appreciate your quick responce. After long time of searching I found The IntuiLink Drivers for 34401A and everything is possible now. Thank you and have a good day. ちなみに、マコトさんは日本人でしょうか？宜しくお願いいたします。

[Makoto]

>  ちなみに、マコトさんは日本人でしょうか？宜しくお願いいたします。

Yes, I am Japanese working for KIKUSUI.