Communicating with RND Labs power supply over LAN

[Ron68]

Hi all,

I just got the RND 320-KD3305P programmable 3 channel DC power supply at 150W, and thought I should make a little program to control it.

Using an ethernet sniffer (Wireshark) I found most of the commands, except the tracking information.

Taking a chance, I ask for STATus?, a rather typical SCPI command, and then I do get 8 bits encoded in ascii back, and it does indeed seem like the 4 least significant bits indicate tracking status as they vary with the tracking modes.

But then - guess what? - when I turn ON any of the channels, the device gets a hiccup, resets the tracking and turns off all channels, behaving like nothing really happened at all. Groundhog day syndrome?

Well - at least there is a response. Better than nothing, I assume.

It is amazingly easy to control these devices over UDP, using separate client and server components, and the communication is fast.
I am using Delphi.

But isn't this behaviour quite strange? Maybe "STATUS?" is interpreted as an input command, but the questionmark should ideally override that, well - depending on the "intelligence" at the other side, i.e. the coding in the device.

The proprietary software was not that much to write home about, but the unit seems to be working well.

[H.O]

They call it programmable but they make it quite hard to find how to actually program it. Did it come with a CD and if so, have you checked if there's aditional documentation on it?

Anyway, that's a rebranded Korad supply. I managed to find a Korad manual for the KA3300 series, it's not the same supply but it does have some information on the commands it accepts: https://familab.org/wiki/images/1/11/Korad-KA3305P.pdf

[Ron68]

Your suspicions were correct - I found the programming manual on the CD-ROM...have almost forgotten that they even exist these days.

Yes, it seems to be a Korad unit, some modification of KD3305SP but without the memory buttons.

I query the voltage and current of both channels in a loop, but when doing the status query something goes wrong, as the unit will not properly turn on.

The STATUS? command is clearly for output.

Thanks for the link, I found that the other day and it did offer some clues.

[tooki]

Yes, it seems to be a Korad unit, some modification of KD3305SP but without the memory buttons.

Huh? It’s a completely standard KD3300 series: http://www.koradtechnology.com/product/13.html

(Not sure which model you’re saying it’s a modification of; KD3305SP doesn’t exist.)