Emerson Exchange 365

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Modbus communication

Hi All

I have EIOC connect with 3rd party PLC , have soft module for communication status of LAN cables for primary and secondary attached the snapshot shown primary CND status could please advise what meaning of 4 & 2 that compare the status with them.

Hassan.hameed

• 11 Mar 2021 5:28 AM
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• Andre Dicaire

  

  • 11 Mar 2021 3:55 PM

  The expression viewer provides a hierarchical view of a Condition Block expression. It has the original expression shown in the top, how it logically breaks down and is evaluated, and in the third box shows you the current state of each Parameter reference.
  
  In this case, you appear to be evaluating a PDT status "//***CP-EIOC-1/P01/UPS_A/STATUS.CV", which is shown to be ??? or not communicating. So the expression is evaluating to false.
  
  The numbers correspond to the following:
  
  0 - Good
  2 - Device No Comms
  Both primary and secondary communications are lost with the device.
  3 - Device Primary Network No Comms
  Only primary communications are lost with the device.
  4 - Device Secondary Network No Comms
  Only secondary communications are lost with the device.
  5 - Logical Device RPI Fault
  An Ethernet/IP device has reported that it cannot maintain the configured reporting rate.
  6 - Logical Device Problem
  A problem has been detected on a logical device and none of the statuses apply.
  
  If you look in Diagnostics and right click on the STATUS parameter and select Help, the Diagnostic Explorer has this information for all the device types. However, the numbers are not indicated. I'm working from memory here but you can quickly check on your system to see if my numbering aligns. As I recall, the value of 1 is not used. Also, I don't believe the EIOC can report more than one issue at a time, so the Highest number shows up if multiple conditions are true.
  
  Back to the condition expression viewer, this tool shows you the result of the expression as viewed from the workstation. It reads the Parameter paths contained in the expression and then plugs them into the expression to evaluate the result. If for instance the workstation is unable to communicate with the EIOC, the parameter results would be ????. The expression in the EIOC itself would of course evaluate correctly.
  
  There is also a known issue with the Condition Viewer. I've run into this a couple of times so if this turns out to be the case, please confirm. When you configure a Condition block expression, you may have entered the path in lower case. The path is parsed successfully and the CND block accepts the expression and works. However, when you open the Expression viewer, it uses this lower case path to read the value and this fails, resulting in the ????. To make this harder to determine, the path is presented in Upper Case in the viewer. And somehow, when you view the CND block again, the path is presented in upper case. To fix this, I had to delete the path in the expression and re-enter it in Upper Case, and download. After this, the value was correctly read in the Viewer and the expression logic resolved as expected. Note that this issue in no way affects the run time, but it makes it hard to use the expression viewer.

  Andre Dicaire

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