Siemens SINUMERIK 840 sl Manual page 54

Diagnostics
8.3 Key test
Operating functions
● Function of the keys and their associated LEDs:
When pressing a key, the associated LED is switched on.
● Function of the rotary switch
Each time the rotary switch is turned, an LED is switched on in sequence in the form of a
running light.
● Function of the key-operated switch:
When the key-operated switch is turned, positions 0 - 3 are displayed by 0 up to three LEDs.
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Machine control panel: MCP 398C
Manual, 07/2018, A5E43199783B AB