Da Sid Mon (Customer) asked a question.
MY LOVE HATE RELATIONSHIP WITH PRODUCTIVITY (a brief vent)
I've been a early supporter of the Productivity and used the 3K series EXTENSIVELY in a business I built (& sold) in part due to Productivity's ability to let me accomplish so much in so little time. I really believe that this series of controllers are the BEST out there.
That being said, there are some things about them that are disappointing and it would be great if FACTS could address and fix.
- Never used the low battery error bit before today in my ladder but decided it would be a good idea to be able to signal to operators/maintenance personnel that it's time for a BAT change. Have not tried on the 3K or 2Ks runing at my current shop but the 1K I'm working with now shows a low battery (even though I just bought this controller). I just so happen to have a couple of spare batteries (purchased from AutoDir 2 weeks ago). Changed out the battery and still getting the low voltage bit error. Decided to look at the Battery Voltage Tag in Dataview. That says 0 volts. OK, let's get the multimeter on that Battery and test it. 3 Volts. WTF? So BOTH the Low Voltage Bit and the Battery Voltage functions are WONKY.
- The HSC Module for the 1K series is really a let down if you have ever used the HSI Modules available for the 2K & 3K. There is now Current Velocity Tag available making it more difficult to use this module for a flow meter application. It's probably fine for motion control but if you trying to measure flow, prepare for a mind twist and a few lines of ladder to get it to do what you want. ALSO the Help file documentation mentions a Time constant user setting that doesn't exist (probably a result of copy and paste from the 2K & 3K Help files and someone not really carefully proofreading). On the positive side, I'll take a wonky P1K HSC over DirectLogic Hi-speed Counter any day.
- The Thermocouple modules that I used for a P2K project were so unstable that they proved to be useless and pretty much convinced the Major Aerospace Company that I was working with on a Temp Control System to produce parts for the US Military that Productivity is Junk-embarrassing for ALL of us.
OK, I'm done- Rant over. Like I said, I'm a fan- I just want it to be better.
THX
"The Thermocouple modules that I used for a P2K project were so unstable that they proved to be useless"
In this instance what does unstable mean?
Not knowing OP's application, I found on the P2K if each temp zone DO NOT SHARE the same ground, when one zone is not used, the others are effected and the temps are unstable. I had an application where I used one thermocouple card per zone. It was a terrific waste but an improvement in cost and parts availability over the obsoleted Siemens controller it replaced.
Potential ground loop issues, the same as with Da Sid Mon's case. From the data sheet, I couldn't tell how the P2K TC card is designed. There should be no "common ground". Each input should function as an isolated analog input with no "common" negative. I would like FACTS personnel to explain internal circuitry in the card.
OK, TO clarify... I was using 4 of these Modules to measure Temp at many points on a large surface. The values returned to the controller jumped sometimes as much as +/- 50 Deg F. Now, I do realize that a little variation is normal but even after applying digital filtering/ averaging/ buffering to the signal I was never able to get stable meaningful values to use. The end solution was to purchase a gang load of solo Temp Controllers- Run the J-Type Thermocouples in to those Solos and then MODBUS to the PAC to get good values. Interesting how the exact same thermocouples runing into a Solo controller were able to give me a good value huh? Of course purchasing 20 Solo Controllers at over $100 each took a major bite out of the profit on this job. Many calls to the AWESOME Tech Support Dudes could not resolve (I do NOT blame them- those Dude's are TOPS in my Book). It's just crummy HArdware and FACTS Engineering just puts their heads in the sand and says-- "Oh Yeah- That's normal" PFFFT. Maybe this module might work with 1 or 2 TC's with a 6" Wire but I don't know about you- I'm not really happy about working with restrictions like that?
Were these grounded or un-grounded TC's? At first blush this sounds like a ground loop issue and not necessarily a card issue. Why the Solos wouldn't exhibit the same issues is interesting.
What I have noticed, in general (with my experiences), is that PLC's and other process controllers do a relatively poor job of cold reference junction compensation when it comes to TC's. Data acquisition platforms (like NI cRIO) do a much better job with this. Typically I see 1-3 deg C temperature error due to cold reference junction temperatures. Fluctuations of +/- 50 deg F is something different beyond CRJT. Typically when I see something like this, this is an open, poor contact, ground loop, static or the like.
Hey guys, I think I can answer a couple of these questions.
Low battery error - Check the firmware in the PLC and upgrade if necessary. In versions prior to 1.2.8.30 there was a problem reading SRAM data on power-up, resulting in corrupted real-time clock and battery data. The problem was more pronounced on the P1-540 but we did get a couple of reports of the P1-550 experiencing the same problem.
Frequency/velocity measurement on the P2-02HSC - Sid is correct, there is no velocity feedback for the P1-02HSC. It’s intended to be a low-cost solution for mostly position-type applications and the hardware doesn’t support the interrupt needed for on-board frequency measurements. As you know, you can calculate the frequency in logic but that isn’t as accurate or repeatable as an on-board measurement.
One reason the Solo, single-loop controller would read a stable temperature when the PLC module didn't is due to fact that the PLC module is non-isolated. If you think about it, the Solo has a single thermocouple channel while the module has either 4 or 8 channels. Any difference in potential between thermocouples wouldn't affect a single channel controller but would a multiple channel, non-isolated module. I'm not suggesting that's the problem that Sid experienced because I don't have all the details. I've reached out to him to see if he has time to discuss his particular situation in more detail.
Thanks for all the replies and advice. Here's a couple of updates/follow up thoughts...
I did have a FW version .23 and updated to the latest .27- still no joy. Same problem. Battery Low Bit remains on with a full 3 volt multimeter reading battery :-(
As far as the TC module is concerned... Yeah, I understand about grounding loops and the like BUT here's the bottom line- if you're going to release a multi-channel module, build a circuit that takes these things into account and doesn't leave the customer struggling to figure it out. I mentioned the Solo controller being able to give a clean reading- what I did not mention was that A. while working on this project the client had a multi channel Temp Datalogger that used the very same set of TC's to check/calibrate. They used this unit throughout their plant to check the various systems using TC's. This multichannel unit was able provide stable reading with the same set of TC's (weird huh?).
Also, during the whole trouble-shooting discussion with AD Tech support staff, it was disclosed to me that this problem has been noted and addressed with FACTS. BECAUSE... while trying to diagnose this issue an experienced (& IMHO highly respected) Tech Person set up an AB controller with a similar module config along side the productivity and the AB rig gave a clean reading while the Productivity produced erratic/unstable values. This resulted in this person talking to FACTS about it and as far as I know nothing was ever resolved.
Sometimes you're the bug & sometimes your windshield- I'm sorry to say that IMHO the Productivity TC modules are The Bug and I would advise to my fellow S.I.'s out there who want to avoid countless hours of suffering- getcha yourselves a 4-20mA Temp sensor and go the analog route- you'll thank me later. Generally speaking FACTS does a fabulous job but there is no other way to say but this module just kinda does the same thing that a Vacuum cleaner does (I used a dif word there but the editor told me that word wasn't allowed LOL). I hope it gets better cause I do have applications where this module would come in handy.
All things considered though the Productivity series of controllers is BY FAR the best thing out there and considering the price even with it's funky quirks, it's still my #1 go to.
I have a couple of questions on the CPU with the battery issue:
1.) Is it a P1-540 or P1-550?
2) If you click on Setup>Set CPU Time/Date, are you able to successfully set the time and date?
These two things were related to the problem firmware 1.2.8.30 corrected. Usually, when the battery error triggered and battery voltage was not readable, the real-time clock data was reset to Jan. 1st 1970 and you could not adjust it. If the firmware update didn't correct the problem then I suspect a hardware problem so you can RMA the CPU and get a replacement. If it's out of warranty, let me know and I'll make sure you get a replacement.
It's a 550. Yes I can set Date and time but, I've been using the new Timesync instruction to do it daily. I have another 1K (550) here on another build. We fired it up today and that unit performs normally out of the box. So, it appears that I just have a bad unit. Back to GA she goes with a replacement on the way :-) I'm thinking that will resolve the issue. I'll LYK what happens.