PLUS+1 Hardware > I/O Modules

IOX024 Pulsing/Flashing Outputs


Heyllo I am having issues with Pulsing/Flashing outputs in my application.

Hardware comprises of a DM430E and IOX024.

I have a simple PI loop circuit, a 0.5-4.5V pressure switch on C1p10 is functioning correctly, the signal input is reading steady.
But my PWM output C2p03 to the coil is turning on and off at approximately 3hZ.

I have checked my code to ensure no funny business, changes the PWM frequency on the group from my desired 160 back to 4000hZ but nothing.

I've even tested all the other outputs as PWM and/or Digital Outs in all possible PinConfigs and I am getting the same on and off at 3hZ.

CAN comms issue I have checked that and no errors there, I believe I can rule that out.

Does anyone have any ideas? I assume this hardware config (DM430E and IOX024 is proven/compatible)?

If you put a checkpoint on the PI loop output is that reading steady?  If not then I guess post your PI loop logic here.

If so then are the repetition times and timeout time settings for your I/O module all set to default, or might something be off?  See attached for the default settings.

Hi Tom yes I put checkpoints in the program for the PI loop output and then the PWM output of the loop, no issues there, constant output as desired.

I found that if I set the DefOutputValue (which is what the I/O module should do if comms are lost) of one of the MFOutputs to 1/True.
Consequently I then did not have any Pulsing/Flashing of that output, proving that it was a comms issue.

So then on a whim I changed the default settings of TimeOut_Outputs from 100 to 500ms.
Problem solved; kinda, I find on power up of the display and i/o module the outputs pulse for a few seconds, I'm assuming this is as the display and I/O module are establishing comms, so obviously there there is lots of traffic there, causing a >500ms delay on the output comms.

Unfortunately I cannot find any API documentation on the IOX024 module that elaborates further on the default settings.
I checked similar MC024 API documentation but there is nothing similar/referencing to TimeOut_Outputs

I don't believe that I could/should be overloading the DM430E processors with the program, is there anyway to test/tell?
Bus load is on average 6% as viewed with the service tool connected.
The screen definitions I believe are simple, only a pressure feedback numerical and bar graph display and numerical pressure input value,
I have similar on 3 different screen definitions, each controls/inputs to 3 PI loops and thus 3 PWM outputs.
Or is that pushing the envelop for the DM430E capabilities?

I'd be a little surprised if you were overloading the display's processor, but three PI loops might be doing it.  You might check to see what your ExecTimeWork, ExecTimeOut. amd ExecTime are set to.  Maybe you need to request a slower processing time (ExecTimeOut)?

Tom I tired changing the ExecTimeOut default of 100ms to 500ms, this did not rectify the issue, all it did was increase the time between pulsing, it was still there.

I'm still stumped as to what it could be.

Adding more to the story, I've just complete testing another project, again a DM430E, and this time a OX024, same issue can be found, Pulsing/Flashing Outputs.
This project program only has 1 PVEA output, no PI Loop.

So I can confirm/assuming the following;
Program not at fault
No particular model Expansion I/O modules at fault

The only constant here is the DM430E and Expansion module Outputs.

Can anyone comment to confirm that have used a DM430E and Expansion module Outputs successfully without issue?


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