HMI failure?

[ptonsparky]

Do HMIs fail?

Customer was trying to explain how he wanted a series of motors to start/stop. What he explained was what he should already have but when he pushed the Start for M1 on the display, M1 & M2 started. This happened several times during our discussion, then wham, only one started. Try again and two started. An operator confirmed later that you had a 50/50 chance of one or two starting depending on star alignment and mouth position. My first thought was an overlaping button display but placement of the fingertip did not seem to change anything.

We have moved several motors and of course now this is "our problem" even though we did not change any programing.

 

[jim dungar]

Do HMIs fail?

Customer was trying to explain how he wanted a series of motors to start/stop. What he explained was what he should already have but when he pushed the Start for M1 on the display, M1 & M2 started. This happened several times during our discussion, then wham, only one started. Try again and two started. An operator confirmed later that you had a 50/50 chance of one or two starting depending on star alignment and mouth position. My first thought was an overlaping button display but placement of the fingertip did not seem to change anything.

We have moved several motors and of course now this is "our problem" even though we did not change any programing.

The odds of the of the logic 'changing' itself and then continuing to operate are so remote, I would not even consider it. Has it ever worked correctly for a period of time? It sounds like there is a 'contact race' in the sequencing logic. Is there a feed back signal from each motor prior to the next one starting? It is possible that the feed back signals are no longer doing what they were intended to do. For example; an incorrect wiring where the "running" and "up to speed" contacts have been swapped on motor #1.

 

[ptonsparky]

I don't know the programing logic, no software for this plc, but the wiring to starter is very simple. An output from PLC pulls in the starter which closes an aux contact sending an input back to the plc. Interlocking is done with the PLC. Both manual & auto start are via the PLC/HMI and I can't imagine this part of the program being complicated at all. A simple BSR & BSL would more than suffice in auto. Not a high speed process.

We just started up for the season so sporadic operation has been around for at least a year if the operator was familiar with the problem.

 

[JWCELECTRIC]

I don't know the programing logic, no software for this plc, but the wiring to starter is very simple. An output from PLC pulls in the starter which closes an aux contact sending an input back to the plc. Interlocking is done with the PLC. Both manual & auto start are via the PLC/HMI and I can't imagine this part of the program being complicated at all. A simple BSR & BSL would more than suffice in auto. Not a high speed process.

We just started up for the season so sporadic operation has been around for at least a year if the operator was familiar with the problem.

Tom,

What device is calling for these pumps to start within the system (pressure, level, flow etc)? The plc could be recieving different signals at the same time causing the motors to start randomly.

 

[Jraef]

If you moved motors, did you move motor lead circuits? Maybe they ran unshielded control wire and if so, could you have moved a power circuit too close to a control circuit and are now getting an inductive signal into the PLC inputs? Evey now and then people would ask me to reduce costs by not using shielded control cable, saying "we won't ever run power wires close to them". But I always refused to cut that corner because, as we all know, Murphy Rules...

 

[jim dungar]

I don't know the programing logic...

If you do not know the logic, or at least the correct sequence of operations, it will be almost impossible to determine what is wrong.

Are your aux contacts opening and closing correctly?

 

[ptonsparky]

I was mostly wondering if the HMIs ever fail in such a manner.

We have contacted the mfg of the control a & they will be glad to tell us the sequence for $150/ hour. Pocket change for my customer so out of my hands until we get an answer...in a couple weeks.

 

[whillis]

I was mostly wondering if the HMIs ever fail in such a manner.

We have contacted the mfg of the control a & they will be glad to tell us the sequence for $150/ hour. Pocket change for my customer so out of my hands until we get an answer...in a couple weeks.

I've built a lot of systems with HMIs and they either work as programmed or not at all. I agree with the other posters that if it worked properly before then likely some wiring got messed up in the move.

 

[ptonsparky]

I've built a lot of systems with HMIs and they either work as programmed or not at all. I agree with the other posters that if it worked properly before then likely some wiring got messed up in the move.

I have only done a handfull of HMIs and none have failed..yet. From the operators experience, it works the same as before the move. Sporadically.

 

[whillis]

From the operators experience, it works the same as before the move. Sporadically.

Well, in that case it's probably a program issue and nothing to do with your work.

PLC logic can be frustrating at the best of times. Right now I'm working with a G&L product that's controlling 7 axes of interpolated motion and the code doesn't always behave as it should according to the programming manual. You learn as you go what the various quirks are and hope the testing catches any you missed, but sometimes stuff like what you've described gets out.

 

[Electrician4life]

I was mostly wondering if the HMIs ever fail in such a manner. QUOTE]

I am currently working with Cimplicity Hmi's from GE Fanuc and we have found them to be rather delicate. If left in an environment that fluctuates in temperature, they tend to either freeze or doesn't respond correctly to the input pushed on the screen.

 

[petersonra]

Unless you are well versed in programming both the HMI and the PLC, and have access to the software to configure both, it is likely you won't be able to solve this problem on your own.

This has all the feel of a software bug somewhere in the HMI or the PLC.

A lot of hacks out there doing PLCs and HMIs.

 

[jdsmith]

I was mostly wondering if the HMIs ever fail in such a manner. QUOTE]

I am currently working with Cimplicity Hmi's from GE Fanuc and we have found them to be rather delicate. If left in an environment that fluctuates in temperature, they tend to either freeze or doesn't respond correctly to the input pushed on the screen.

What type of HMI hardware is it? Cimplicity is the software, not the hardware HMI screen itself. I have a Cimplicity application that runs on computers now and I was thinking about putting it on some touchscreens, just curious to see which ones you have to make sure I take a very close look at them before I plan a large installation.

 

[ptonsparky]

Unless you are well versed in programming both the HMI and the PLC, and have access to the software to configure both, it is likely you won't be able to solve this problem on your own.

This has all the feel of a software bug somewhere in the HMI or the PLC.

A lot of hacks out there doing PLCs and HMIs.

I am as good a hack as the rest but spending +$1200 just to look at the HMI setup was a bit much, not counting the learn curve. $350 for plc software I could use again isn't so bad but the customer has moved on to different issues. Funny how something can be so important at the moment, but give it a week or two and it just gets shoved under the rug.

 

[petersonra]

I am as good a hack as the rest but spending +$1200 just to look at the HMI setup was a bit much, not counting the learn curve. $350 for plc software I could use again isn't so bad but the customer has moved on to different issues. Funny how something can be so important at the moment, but give it a week or two and it just gets shoved under the rug.

Its about having the right tools for the job. The cost is easy to justify if you use them any significant amount.

The learning curve is usually far more expensive than the software.

 

[machasman]

whats your process

whats your process

what is your process? If you are pumping water then you may have a float backup. in most configurations once the water in the vessel gets to low a LWC float will turn your pumps off and may drop your PLC control I wont go on as I don't know if this is even helping

 

[ptonsparky]

This is simply a series of fans and other motors that should start in a certain sequence then stop in reverse order. Other than speed control of a group of fans and one auger, the PLC only functions as an interlock for this portion of the process. Once the system is up and running the complete process is more complicated and automated but for this group of motors the PLC is still just an interlock.

 

[Hunter J]

What brand of HMI and PLC? If you post the files I or maybe someone else can open them and print them to PDF if that would help.

 

[johnnebr]

If you have a GE PLC I might have soft ware for you. Would need to know wht model that you have? I am in nebraska.

 

[Hunter J]

I am also in NE with AB software.