adccommunitymod (AutomationDirect) asked a question.

D2-250 CPU Comes out of run mode

Created Date: May 15,2006

Created By: gtremblay

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WE have a project in which the D2-250 periodically comes out of the run mode. If the unit is powered down it will power up again in the run mode. Does anyone have a solution for preventing this?


  • adccommunitymod (AutomationDirect)

    Created Date: May 15,2006

    Created by: Tech Guy

    Usually this is caused by one of two things.

    1) Operator who likes to fiddle with buttons and switches (Run/Term/Stop switch). If it tends to always happen during a particular shift, then this is often the culprit.

    2) A CEMF (Counter ElectroMotive Force) spike from inductive devices being switched off or possibly lightening. Use Diodes or MOV's (Metal Oxide Varistors) on all coils and a good surge suppressor for the incoming power to the PLC. Occasionally the spikes com in through the COM ports, but this is fairly rare.

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  • adccommunitymod (AutomationDirect)

    Created Date: May 15,2006

    Created by: gtremblay

    WE have a project in which the D2-250 periodically comes out of the run mode. If the unit is powered down it will power up again in the run mode. Does anyone have a solution for preventing this?