Contrologix scan times

A question for the Contrologix/FactoryTalk experts. I have a Contrologix 5572 connected on a system of about 13 nodes by ethernet and several RIO racks. I have a Panelview+ 1500 running factoryTalk. My processor scan times show about 8-9mS range. When I press a button on my screen a lot of times the same contact in the program does not respond. I think this is a system (ethernet/RIO) timing problem. Anyone ever run into this? Know how to correct it? Maybe point me in the direction of what to look for? Thanks.

Hi

You could look at the update rate for the screen on the HMi.
You would need rs view me and right click on the screen and you will see the update rate.

It's were I would start anyway

Donnchadh

donnchadh said:

hi

you could look at the update rate for the screen on the hmi.
You would need rs view me and right click on the screen and you will see the update rate.

It's were i would start anyway

donnchadh

Click to expand...

I second donnchadh's suggestion.

Are these buttons that you programmed? Have they ever worked?

The scan time of the CLX seems fine. I would look at the communication between the HMI and PLC.

However, on the buttons, look at the hold time. Basically, when you create a button on the HMI, when you press the button, you can make it hold for defined amount of time. I don't have ME open now, but I think the default is 50ms. So, that should work for you.

Have you run the AB Ethernet capacity tool? This is a free tool from AB.

James

The update rate of the screens shouldn't matter. The default times are one second, and I have never had a problem.

James

hmmmm if what others have suggested doesn't work it may be so your button command is unlatching or getting reset before the code has a chance to see it. What kind of buttons are you using? Momentary or maintained buttons, you would want the code to unlatch the button, that why you have control as opposed to the HMI.

dbh6 said:

hmmmm if what others have suggested doesn't work it may be so your button command is unlatching or getting reset before the code has a chance to see it. What kind of buttons are you using? Momentary or maintained buttons, you would want the code to unlatch the button, that why you have control as opposed to the HMI.

Click to expand...

Totally agree with that. The HMI should just turn it on, and the PLC should turn it off once it has been "seen", and acted on.

Thanks everyone for the input. To answer some questions:
These are screens I've created.
The screens refresh rate is 1 second but I've had it as low as 0.05 seconds, it made no difference.
The button I'm pressing had a 250mS hold time but I increased it to as much as 5 seconds and response improved some.
Even with the button response time set at 5 seconds, I programmed a latch rung to capture the buttons contact in the contrologics program and at least 50% of the time did not latch in when the button was pressed.
My contrologix rack consists of:
Slot 0 processor
Slot 1 ethernet module connected to 14 ethernet devices and 2 flex I/O racks
Slot 2 ethernet module connected to the panelview
Slot 4 DHRIO module
Slot 5 RIO module
Slot 6 RIO module

I still think this may be a timing/polling problem but I would need help as to where to look for a solution.

So, the only thing on the network in slot 2 is the HMI?

Yes, the screen update would have no effect. If your scan time is 9ms, the default hold time should work.

Try this:
1. Create a momentary push button.
2. Use direct reference tag, not HMI, so create tag in PLC, for example, testpb. Then the connection in the HMI would be {[shortcut]testpb}.
3. Create a rung XIC testpb OTL testlatch.
4. Then test. When you push the button on the screen, does the testlatch go high?
5. Toggle the testlatch to run again.

Normally, using the above as an example, after testlatch I would have an unlatch for testpb. Doesn't make the button work any better, but does prevent "sticking", which can happen.

James

The ethernet modules in slot 1 and slot 2 both plug into a common ethernet switch. In my logix5000 project tree the HMI is the only thing sending data to the ethernet module in stot 2.

Again, create a brand new momentary pushbutton. Don't copy and paste an existing one. Create one, make sure it is momentary. Then create some test tags. To eliminate network issues, can you plug HMI directly into the ethernet module in slot 2.

FYI, if the HMI is the only thing connected to slot 2, you don't need the module in the tree. It is not required.

James

I created the momentary PB with a latch bit in the program. It works every time. Maybe I haven't had enough caffeine yet this morning, what does this prove. Obviously something is different.

It means scan time is not an issue. It means your hardware is fine. To me, it tells me when you created the HMI objects, or PLC code, something wasn't correct. Make sure you didn't use a maintained pushbutton. When you said it works 50% of the time, that was my initial thought. However, it could be that you were using tags that being "manipulated" somewhere else in the program.

Without seeing either the HMI or PLC applications, I can only guess.

James

Thanks to everyone for all the help. The problem ended up being the tags for the old panelview (which I'm replacing) had the tags alias to a RIO card. Changing the alias tag to a base tag solved the problem. Thanks again.