Emerson Exchange 365

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Troubleshooting EIOC EVENT_LIMITED State and Input Transfer Failures

Hello and Happy New Years,

Over the last while we have been having issues with one of our EIOC's getting an EVENT_LIMITED. state and Inputs Transfer Failure description. From what I can see nothing has changed in our system to cause more loading on the network. I saw in one post regarding VIM2 cards that it has to do with the Pro+ receiving to many events.

Can anyone explain in more detail the relationship between the Pro+ receiving too many events and the EVENT_LIMITED state?

What could cause this issue and is it more likely to be on the EIOC side or PRO+ side?

We are on DeltaV 13.3.1. The performance index for the EIOC says 5.0. There are 46 device connections using Modbus TCP. There are 239 modules. Going back in the history I see several of the modules have had this issue come up briefly every couple days. However, on the 23rd and the 29th of December we had 2 times where the group of modules associated with our mill drives go into this state. All 4 drives had this issue for a couple hours on both dates and it is the first time we have seen it. When I looked at a trend in PHV for an analog value it was still being read, so data is coming but maybe 5 times a minute we would enter the EVENT_LIMITED state. 

Thank you for your time,

Michael Sovereign

Link to VIM2 discussion about EVENT_LIMITED

(+) Emerson Exchange 365

• EIOC
• DeltaV #DCS
• EVENT_LIMITED
• Modbus TCP
• Inputs Transfer Failure

Michael_Sovereign

• 2 Jan 2024 3:18 PM
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6 Replies

• Andre Dicaire

  

  • 2 Jan 2024 5:02 PM

  I would first suggest you log a call with the GSC to get more clarity on the Event_Limited state. I've not seen this come up, so I'm not sure where you are seeing this. Is this an event/message that is being recorded in the Ejournal under this module? Can you show the entire message? Does it occur for each module?
  
  Events are sent by the controller and expect a confirmation of receipt. If the server is unable to respond for any reason, the event can be resent once the connection is restored to the server. The events are buffered one deep so if the module updates the event, say the Alarm change of state, the Ejournal will indicate that one or more events have been lost.
  
  Events are timestamped in the controller and can be received out of order (chronological order),, They will be displayed correctly when sorted by time. I'm wondering if the EVENT_LIMITED is a per module message or an overall Ejournal performance limit. I can't tell from your description what the context is of this event.
  
  This issue will have nothing to do with the ethernet device traffic, in my opinion. Module level events are generated when the module executes based on its configuration. If the issue were loading on the Ejournal server end, I would expect it would affect all modules everywhere. But if the modules get into a state that they generate too many events, say LogEvents in expression based blocks, that might explain why this shows up on your 4 drive modules.
  
  My guess here is your module configuration may be too Event Heavy. You indicate that the EVENT_LIMITED is related to modules. So I'd look at how many events you might be generating. Do you use LogEvent in calc blocks? Do you drive multiple LogEvents in the same expression? How many are being created in each module scan? Are there other events recorded with the module during this time?
  
  The DeltaV Controllers will limit certain actions to protect the integrity of the system from an overzealous module. Things like, Divide by 0 or infinite While Loops will not crash the controller, but the associated expression is flagged and stops executing until the issue is fixed. I'm wondering if ther emay be a limit on the number of events a single module can generate, and if you have input transfer errors along with log events and such, maybe from time to time these modules exceed this.
  
  As I said, I have not seen this particular event. A list of the events for the module(s) at the time this message is seen should reveal the number and type of events recorded per module execution. The GSC would be asking for this. information.

  Andre Dicaire

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• Michael_Sovereign

  

  • 2 Jan 2024 11:11 PM

  In reply to Andre Dicaire:

  Hey Andre,
  
  Thank you for replying. These are Modbus landing modules, none of the block have LogEvent inside the module, but many of the registers landed on internal read parameter blocks are connected to internal write parameter blocks and are collected by the historian. However, the module has multiple registers set up like this and not all of them went into the EVENT_LIMITED state. I will contact GSC tomorrow on the issue as well to ask for clarification and to share it once I understand it better.
  
  I have pasted a sample of my Ejournal below. Sorry if it's messy. The total time is about 2 seconds from top to bottom.
  
  Thanks again,
  
  Michael Sovereign
  
   
  161 12/29/2023 9:39 EVENT PROCESS GRIND 3210-EIOC-9303 GRIND_BALL_MILL 3210-II-4772 Ball Drive Output Current ACTIVE 4-INFO Error Cleared I/O Input Failure
  162 12/29/2023 9:39 EVENT PROCESS GRIND 3210-EIOC-9303 GRIND_BALL_MILL 3210-JI-4772 Ball Drive Output Power ACTIVE 4-INFO Error Cleared I/O Input Failure
  163 12/29/2023 9:39 EVENT PROCESS ELEC 3210-EIOC-9303 3210VFD021MC-RD 3210-VFD-0021 MV7312 MB Data Read ACTIVE 4-INFO Error Cleared Inputs Transfer Failure
  164 12/29/2023 9:39 EVENT PROCESS ELEC 3210-EIOC-9303 3210VFD022MC-RD 3210-VFD-0022 MV7312 MB Data Read ACTIVE 4-INFO Error Cleared Inputs Transfer Failure
  165 12/29/2023 9:39 EVENT PROCESS ELEC 3210-EIOC-9303 3210VFD022MB-ALM Ball Mill VFD-0022 MB Alarms EVENT_LIMITED. 4-INFO 3210VFD022MB-ALM/R40011 Inputs Transfer Failure
  166 12/29/2023 9:39 EVENT PROCESS ELEC 3210-EIOC-9303 3210VFD022MB-ALM Ball Mill VFD-0022 MB Alarms ACTIVE 4-INFO 3210VFD022MB-ALM/R40009 Inputs Transfer Failure
  167 12/29/2023 9:39 EVENT PROCESS ELEC 3210-EIOC-9303 3210VFD022MB-ALM Ball Mill VFD-0022 MB Alarms ACTIVE 4-INFO 3210VFD022MB-ALM/R40009 Inputs Transfer Failure
  168 12/29/2023 9:39 EVENT PROCESS ELEC 3210-EIOC-9303 3210VFD022MB-ALM Ball Mill VFD-0022 MB Alarms ACTIVE 4-INFO 3210VFD022MB-ALM/R40001 Inputs Transfer Failure
  169 12/29/2023 9:39 EVENT PROCESS ELEC 3210-EIOC-9303 3210VFD022MB-ALM Ball Mill VFD-0022 MB Alarms ACTIVE 4-INFO 3210VFD022MB-ALM/R40001 Inputs Transfer Failure
  170 12/29/2023 9:39 EVENT PROCESS ELEC 3210-EIOC-9303 3210VFD021MB-ALM Ball Mill VFD-0021 MB Alarms EVENT_LIMITED. 4-INFO 3210VFD021MB-ALM/R40011 Inputs Transfer Failure
  171 12/29/2023 9:39 EVENT PROCESS ELEC 3210-EIOC-9303 3210VFD021MB-ALM Ball Mill VFD-0021 MB Alarms ACTIVE 4-INFO 3210VFD021MB-ALM/R40009 Inputs Transfer Failure
  172 12/29/2023 9:39 EVENT PROCESS ELEC 3210-EIOC-9303 3210VFD021MB-ALM Ball Mill VFD-0021 MB Alarms ACTIVE 4-INFO 3210VFD021MB-ALM/R40009 Inputs Transfer Failure
  173 12/29/2023 9:39 EVENT PROCESS ELEC 3210-EIOC-9303 3210VFD021MB-ALM Ball Mill VFD-0021 MB Alarms ACTIVE 4-INFO 3210VFD021MB-ALM/R40001 Inputs Transfer Failure
  174 12/29/2023 9:39 EVENT PROCESS ELEC 3210-EIOC-9303 3210VFD021MB-ALM Ball Mill VFD-0021 MB Alarms ACTIVE 4-INFO 3210VFD021MB-ALM/R40001 Inputs Transfer Failure
  175 12/29/2023 9:39 EVENT PROCESS ELEC 3210-EIOC-9303 3210VFD022MC-RD 3210-VFD-0022 MV7312 MB Data Read ACTIVE 4-INFO 3210VFD022MC-RD/R40052 Inputs Transfer Failure
  176 12/29/2023 9:39 EVENT PROCESS ELEC 3210-EIOC-9303 3210VFD022MC-RD 3210-VFD-0022 MV7312 MB Data Read ACTIVE 4-INFO 3210VFD022MC-RD/R40051 Inputs Transfer Failure
  177 12/29/2023 9:39 EVENT PROCESS ELEC 3210-EIOC-9303 3210VFD022MC-RD 3210-VFD-0022 MV7312 MB Data Read ACTIVE 4-INFO 3210VFD022MC-RD/R40050 Inputs Transfer Failure
  178 12/29/2023 9:39 EVENT PROCESS ELEC 3210-EIOC-9303 3210VFD022MC-RD 3210-VFD-0022 MV7312 MB Data Read ACTIVE 4-INFO 3210VFD022MC-RD/R40049 Inputs Transfer Failure
  179 12/29/2023 9:39 EVENT PROCESS GRIND 3210-EIOC-9303 GRIND_BALL_MILL 3210-II-4772 Ball Drive Output Current ACTIVE 4-INFO 3210-II-4772/AI1/ALM1 I/O Input Failure
  180 12/29/2023 9:39 EVENT PROCESS GRIND 3210-EIOC-9303 GRIND_BALL_MILL 3210-II-4772 Ball Drive Output Current ACTIVE 4-INFO 3210-II-4772/AI1/MLTX1 I/O Input Failure
  181 12/29/2023 9:39 EVENT PROCESS GRIND 3210-EIOC-9303 GRIND_BALL_MILL 3210-JI-4772 Ball Drive Output Power ACTIVE 4-INFO 3210-JI-4772/AI1/ALM1 I/O Input Failure
  182 12/29/2023 9:39 EVENT PROCESS GRIND 3210-EIOC-9303 GRIND_BALL_MILL 3210-JI-4772 Ball Drive Output Power ACTIVE 4-INFO 3210-JI-4772/AI1/MLTX1 I/O Input Failure

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• LaurentB

  

  • 3 Jan 2024 1:49 PM

  In reply to Michael_Sovereign:

  limited event means that there is a hard limit of 5 events per module execution is reach
  
  This is quite normal in a landing module with a lot of parameter linked to a comm. only one comm error can generate a lot of event in this module...
  root causes of comm error can be multiple....may be the device in the other side is saturated by the speed , or one register does noty exists or....
  
  In your case the other side seems to speed speed variator, Are you sure that speed variator is still powered when motor stopped ( Not run at speed 0) ? many time the logic put completey the VSD off and not able to communicate....

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• LaurentB

  

  • 3 Jan 2024 1:52 PM

  In reply to LaurentB:

  just for fun it's very easy to simulate a EVENT_LIMITED into the ejournal. Just create a module with a act block containing 6 lines "Logevent" function

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• Andre Dicaire

  

  • 3 Jan 2024 8:16 PM

  In reply to LaurentB:

  based on the log, pretty clear the limit of five events is being reached, generated by the IO Input Failures, not LogEvents. Just want to note that the events processing is handled differently than the unsolicited communications that would be populating the Historian. So the issue is why are we getting IO input transfer failures. Can you break down the configuration in the module a bit more? you said these were Input external references. Are they wired to an FB of some sort? Is the data form the dataset register consistent with the FB input? wiring a 16bit Unsigned to a Signed parameter? IO input Transfer Failure seems to me to indicate the value was not accepted on the INput paramter of an FB. But I'm not 100% sure of that.

  Andre Dicaire

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• Michael_Sovereign

  

  • 26 Jan 2024 11:33 PM

  In reply to LaurentB:

  Just as you mentioned, and here is what Guardian says about it. I
  
  The EVENT_LIMITED state
  The number of PHV events per module execution is limited to 5. If more than 5 events are trying to report on the same module execution then the fifth one with EVENT_LIMITED state indicates that not all of them are actually showing.
  
  From AP-0800-9249,"Inputs transfer failure" messages are not necessarily an issue as long as the overall control is not affected. In most cases, "Inputs Transfer Failure" is a temporary condition wherein the module parameter is unable to receive data that's being transferred -- possibly due to a temporary lock on the module or parameter (i.e. while it is running or while another module is writing to it).
  
  From AP-0801-5200, “Input Transfer Failure” exists in the module when it is transferring values between function blocks. In other words, there is an error reading the source parameter on a connection between Function Blocks. Normally, it is a connection where the parameter is trying to read a parameter from another module. This can be caused by the reference being in another Controller or the reference is External and can either not be resolved or the External Parameter is in error. If module does not exist in the referenced Controller, download it. Make sure that Controllers are able to communicate with each other. Right click on "Assigned Modules" in DeltaV Explorer and select "View Modules with Errors".

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