I’ll report back and document progress or lack thereof.
would love to hear from any of y’all who are already playing this game, especially if you’ve taught a PLC or other device to interact with your circulator over RS232.
This is my favorite book for doing RS232 stuff. My dad helped write it when he was at Digital Equipment back before it was gobbled up by HP.
It has some good information on different kinds of communication, methods for talking to different kinds of things, methods for figuring out pin usage (since people get weird about, even with there being a standard), etc.
I haven’t used it to talk to my polyscience system… but I have used it to talk to different GCs, printers to get my GC to print directly, micro-computers that do all kinds of stuff, and a few different conversions for older servers / main frame so they could use USB via serial to transfer data, instead of using tapes…
Now you make me want to crack open the dang thing so I can see what all information it has that I can collect, see if I can program some additional alarms and limits for its behavior…
I really like using unexpected tools like this for things like reliability maintenance and operational excellence tracking activities. <3
for others who might want to build controls for their circulator based on vacuum or process temp, there is DIY: Vacuum and Temp Monitor Under $150 (and a couple of other builds linked therein).
Oh sweet. That RS232 book I linked has a lot of diagrams. Many of them are old school parts (harder to find today) but almost all of them can still be used with just a few modifications.
By far my favorite book. I have the first edition… I wonder what extra cool things are in the 2nd edition.
Fwiw if you haven’t already bought one, polyscience is such a jenky brand I really can’t understand why anyone still uses them. The pumps are ass, poor circulation, parts break easily, etc. They really do their best to appear high quality but they’re worse than any of the low tech Chinese shit out there. In my opinion, for a decarb that you need to both heat and cool fast, julabo is the same price just about but they actually work.
Trying to do the same with my julabo corio units. I can control one remotely for free, but if I want to control 2 or more it costs over $2k for the software to do it. Interested to see what you guys come up with.
Which is why I decided to go there…however, the fact that you’d already wandered down that lane and told the rest of the glass what you’d found had slipped my memory.
Certainly wasn’t purchased for this. It’s what I had, and it’s already doing most of the work, I’d just like it to lower the temp from 130C down to 60-70C once it’s told decarb is done.
Getting it to raise its hand when it was done would be a bonus.
Never gonna turn you up
Never gonna turn you down
Never gonna turn you off
Or recirc you…
I’m certainly no polyscience fan. But they’re absolutely better than the garbage chillers I got from ZZKD - the polyscience I have actually works, while the two ZZKD I bought lasted between zero days and two months without dying in easily avoidable and occasionally unsafe ways.
And the polyscience actually hits the advertised temps, and holds them for the most part.
If you can get polyscience stuff for 1/4 to 1/3 of MSRP they’re not a terrible deal. I certainly wouldn’t pay MSRP for one.
Biggest problem is price in exchange for lack of head pressure and flow rate. Sure, you can SET them to -20C…and inside the bath they might REACH -20C…but that will never get pumped or flow through a pipe to get your reactor jacket remotely close to -20C. They can barely pump room temp fluid 5ft vertical, increase the viscosity by 1000 and it’s just a gurgle/disappointment generator.
I’ve got two polyscience 7L that look like I can get their attention via Ethernet, and they have managed most of what I’ve asked of them since they arrived used…not gonna sideline them if they continue to do so…especially if I can leverage @Lincoln20XX’s grudge engineering AND be forced to use python.
I don’t believe the BVV branded version shown here is capable of taking external commands, but I’d have to look at it again to be certain. It took us a second or 12 to find the analog over-temp safety we were up against here. It’s under the BVV label…
So not fully what you are looking for but possibly some of the way there. I was able to find 2 different polysci chiller manuals that had the rs232 communication defined:
Both show a similar format to commands so it may be reasonable to expect your model to talk in a similar fashion. Should be simple to send commands over usb to serial to get some understanding of the communication that you would need. You could also make that connection wireless with my vacuum monitor you linked above. Happy to send you one to play with if interested.
