eRCM Express™ Troubleshooting

Troubleshooting Known Issues

Issue Action to Review for Resolution
Next Step Up and Next Step Down, and all Load Step are invalid when trying to “pack” a discharge line – e.g., very low compression ratios. Likely the issue is the model (eRCM Viewer file) is using a MinRatio limit higher than 1. Hence, if compression ratio goes lower than set MinRatio, then all load steps are affected and thus all load steps area flagged as unusable.

  • Affects: All Versions.
  • Symptoms: All load steps flagged as unsafe.
  • Workaround: 1) Create a new eRCM Viewer file with a MinRatio of 1.00 and upload that new file into the eRCM Express.
    • Note: This is a useful constraint feature, and not a bug. However, most models default to a MinRatio of 1.02 which can lead to operating issues when packing a discharge line.
Communications between the PLC and the eRCM Express box seem to be working, but only zeroes are being returned for most all tags/registers.
  1. Check that the eRCM Express License is installed and valid on the mCore.
    • How to do: See the section “Uploading a License File” in the eRCM Express Manual.
  2. Check that at least one (1) eRCM Viewer model has been uploaded to the mCore and that the model names start with a digit (“1” through “9”)
    • How to do: See the section “Uploading a License File” in the eRCM Express Manual.
  3. Check if the PLC is sending any data in ACI_Input[50] (SetViewerFile, Modbus Reg# 40101). This item is used to specify which eRCM Viewer model to be used within the eRCM Express.
    • Values less than zero (0) or greater than nine (9) are ignored.
    • A value of zero (0) tells eRCM Express to take no action, and to keep using the current modeling file.
    • A value from one (1) to nine (9) tells the eRCM Express to load in the eRCM Viewer models starting with that digit.
    • In generally, this item’s value should be zero (0) if only one file is in the eRCM Express box, and this item never needs changed.
    • If multiple models are in the eRCM Express box, then this item’s value should only get set during Unit Start Up, and thereafter reset to zero (0).
    • If a value in ACI_Inputs[50]/Reg#40101 sets eRCM Express to a non-existent unit (i.e. no modeling file starting with that specified digit), then no data will be returned, and all data items will stay at their initial values of zeroes (0).
  4. If you are using the Allen Bradley communications option, please check to make sure that the setup in the mCore is correct for your Allen Bradley PLC. Specifically, the mCore needs to be set with the IP of the Allen Bradley PLC. If the mCore cannot push data to the PLC, then likely the results will be that the data you send to the mCore will be there in the mCore but data in the PLC will likely remain all zeroes (0’s).
  5. If some data appears updating while other data appears to not update, then the issue may be with the size of the arrays allotted to the data being sent from the mCore. If the local AB arrays are the correct size (or even larger than the mCore arrays), there should be no issues. However, if the local AB arrays are smaller (i.e., fewer elements), then communication issues will persist and data will be corrupt, missing, or may not even update.
Next load step up/down does not return sensible results when using “Field_Ps” feature.
  • Affects: Version 0.5.0 to 1.1.31 mCore.
  • Symptoms: When passing a value in the “Field_Ps” tag, next load step up/down results will not be correct for the current load step.
  • Workaround: Write a value of “0” (zero) for the “Field_Ps” input tag value.  This will turn off that feature and next load step up/down will be correct.
Uploading valid eRCM Viewer files sometimes does not correctly copy those files into the mCore and results in some zero-byte files being created in the mCore that cannot then be used.
  • Affects: Version 0.5.0 and 0.5.1 of mCore.
  • Symptoms: The desired eRCM Viewer file is included in the list of files in the web interface, but when retrieving compressor calculations, all values are zero — all the time.
  • Workaround: In the web interface, click the Clear All Viewer Files button, then navigate to the Import Viewer files upload page and upload the eRCM Viewer files again.
  • If issue is not resolved, try repeating the above workaround a couple of times.
Uploading a valid eRCM Express licensing file sometimes does not correctly copy that file into the mCore and results in a zero-byte file being created in the mCore. Internally, the mCore is not licensed to use eRCM’s calculation methods, and thus does not return useful results.
  • Affects: Version 0.5.0 and 0.5.1 of mCore.
  • Symptoms: Static items Ranges, Number of Load Steps, etc. are still returned, but all registers with performance and control items are returned as zeroes.
    • Note: This issue would only occur if the license file was accidentally removed and the user is trying to re-license the mCore, or if the user is upgrading unit from a Condition Monitor license to an eRCM Express license.
  • Workaround: In the web interface, click the Clear ACI License File button, then reupload the provided license file.
    • If issue is not resolved, try repeating above workaround a couple of times.