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Sigma - Digital outputs do not operate as expected, following an upgrade.


Digital outputs do not operate correctly after upgrading.


Digital Outputs




This issue can occur in two ways;

  • A Sigma V53 CPU card has been replaced with an ARM7 processor card, and the digital outputs no longer operate as expected.
  • A firmware upgrade has taken place, and the digital outputs no longer operate as expected.


This issue has been caused by an early version of SigmaX, which switched the "Hysteresis" function in a DO to on.

In earlier versions of Sigma this did not cause an issue, as the Hysteresis function did not work. But, in later Sigma firmware versions the Hysteresis function has been corrected, and therefore this problem will be experienced.

To correct this issue carry out the following;

  • Start the Sigma client and server.
  • Select the "Display"menu, and then choose "Object Types", then select the CMD option.
  • Starting at the top of the index, work though all folders and locate the CMD objects.
  • For each objects found, edit the object and select the "General" tab, then deselect Hysteresis Control.


  • Repeat as many times as required to modify all objects.
  • Having completed the editing, download the object to the controller.
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Revision #:
1 of 1
Last update:
‎2018-09-06 03:10 PM
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