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ErrorLib — Industrial Fault Code Library

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851

SERCOS: Max. number of active commands exceeded (channel: %d).

Bosch Rexroth · Motion Control

What does 851 mean?

The capacity limit of the internal list that holds NC commands destined for a drive has been exceeded. This error occurs when more than 5 simultaneous active commands are present, representing a serious system error.

Common Causes

  • Number of simultaneous active commands to a drive exceeding 5.
  • Capacity limit of the active command list exceeded.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Review and optimize the operational environment or application logic to reduce the number of simultaneous active commands.

Browse all codes in this manual (60)
Verified technical data. Last updated: April 2026

Related Faults

1287Error during generating the stack for the IdleTask.1288SERCOS state class 1: Overload cut-off %s-axis.1289SERCOS state class 1: Amplifier overtemperature cut-off %s-axis.
Source: Bosch Rexroth Motion Control
Open Manual (Page 61)Search more codes in this manual