LD UDFB Guided Learning Q08: – What would happen if the NOT xEnable condition were removed

Automation and Control
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This article is part of a guided learning series on building and analyzing User-Defined Function Blocks (UDFBs).

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The fault reset network considers both NOT xEnable and xReset as necessary conditions to perform a reset. What would happen if the NOT xEnable condition were removed. Be specific and explore this from the operator’s perspective.

Answer

This is a critical safety consideration. It prevents an unexpected and potentially dangerous restart of the motor. As written, the operator must first disable motor activation signal before attempting a reset. If the reset is successful, the operator may then restart the motors in accordance with the plant’s standard operating procedure.

:writing_hand: Article by Aaron Dahlen, LCDR USCG (Ret.), Application Engineer at DigiKey