Siemens alarm 20000: [Channel %1: ] Axis %2 reference cam not reached

What it means

During reference point approach the NCK did not register actuation of the reference cam within the permitted search traverse. The zero-mark search must start from a position where the cam is still ahead of the axis, otherwise the reference pulse sequence cannot be evaluated.

Likely causes

• axis was not jogged clear of the reference cam before the referencing run was started
• reference cam or its proximity switch defective, misadjusted or stuck actuated
• cam signal input / PLC interface bit for the reference cam not wired or permanently active
• referencing machine data (REFP_MODE, cam assignment, search direction) configured incorrectly
• traversing range too short to reach the cam from the start position

Replacement parts

We supply the following units for this alarm — tested, warranty-backed:

• proximity/limit switch per machine builder drawing

  cable · Check if others ruled out

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