RE: Ethernet to RS-232 Danfysik supply connection issues

[Kathryn Baker - UKRI STFC via Tech-talk <tech-talk@aps.anl.gov>]

Just to confirm what one of my colleagues said, we do send REM commands first, as Danfysiks require being in remote mode to reply. The other thing to be aware of is whether it is an RS232 power supply, they do provide RS422 and RS485 as well. If it is one of those models that uses a multidrop protocol you may need to make sure that the device isn't in multi drop mode, and possibly address the PSU as well - even if it is the only PSU on that line.

You can also put them into remote mode on the front panel of the PSU with most of the ones I can think of.

From the description you gave, I'd look at the remote/local mode as the first set of fixes, and make sure you are addressing it properly (send ADR and the address assigned if there is one) as the second item. Then go on to the advice Mark gives. However, it is worth noting that depending on the setup you have what is displayed on the screen on the Danfysik is actually the settings for the screen to the control module, and not for an external controller such as a computer - they have a different set of BAUD rates etc.

We do actually interact with 9100 and 9700s on site, as well as much of the 8000 range.

Regards,
Kathryn

-----Original Message-----
From: Tech-talk <tech-talk-bounces@aps.anl.gov> On Behalf Of Mark Rivers via Tech-talk
Sent: 24 December 2019 13:39
To: Marissa Kranz <kranzm@uwmcf.uw.edu>
Cc: tech-talk <tech-talk@aps.anl.gov>
Subject: Re: Ethernet to RS-232 Danfysik supply connection issues

 >  Talking directly to  the power supply via an old machine with a serial port also gets no response from the supply.

Here are things to do when trying to get RS-232 to work.

- If you have the manual for the power supply read its description of the RS-232 communication.  It should document how many data bits and stop bits, parity, baud rate, etc.

- Check that the device and the computer/Moxa are not transmitting on the same pin (2 or 3).  Disconnect the cable and measure the voltage from pin 2 to ground and pin 3 to ground on both the device end and the computer/Moxa end.  You will find that either pin 2 or pin 3 is at least -5V while the other is floating. If they both have -5V on the same pin then you need a "null modem" cable that swaps pins 2 and 3.

- The device may be using hardware flow control, and so requires some other pins to be asserted before it will reply.  You may need to enable hardware flow control on the computer/Moxa.

- Make a breakout cable so you can display both pins 2 and 3 on an oscilloscope when you are trying to communicate.  You should see the characters being sent from the computer/Moxa as square waves on one pin and any response from the device on the other pin.  If you see any response from the device then you probably have a problem with parity, stop bits, baud rate, etc.

Mark

________________________________
From: Tech-talk <tech-talk-bounces@aps.anl.gov> on behalf of Marissa Kranz via Tech-talk <tech-talk@aps.anl.gov>
Sent: Monday, December 23, 2019 6:29 PM
To: tech-talk@aps.anl.gov
Subject: Ethernet to RS-232 Danfysik supply connection issues

Hello,

I am trying to establish remote control of a Danfysik system 9700 magnet power supply via a Moxa ethernet to RS-232 adapter (NPort 5150). We can talk to the Moxa adapter just fine and confirm that message sent from EPICS or a terminal successfully reach the adapter, but the supply never responds nor sends any error messages or anything. Talking directly to the power supply via an old machine with a serial port also gets no response from the supply.

Has anyone ever used the Danfysik system 9700 and have any wisdom they could offer?

Thank you,
Marissa Kranz

--
Marissa Kranz
Research Engineer
UW Medical Cyclotron Facility
University of Washington School of Medicine
425.246.4964