12 Functional Descriptions 09.95
12.11.1 SIPOS absolute encoder up to SW 4
12.11.1.4 What happens on warm restart (POWER ON)
When NC MD 1808* bit 0 "Axis with absolute encoder" is set, NC MD 1808* bit 3 "Absolute
offset valid" is checked for the relevant bits. If both bits are set, the axis-specific interface
signal "Reference point reached" is set on warm restart.
12.11.1.5 Special case ”Parking axis”
The axis-specific interface signal "Parking axis" deletes the signal "Reference point reached"
even for an axis with a SIPOS absolute encoder.
12.11.1.6 Absolute encoder error
The absolute encoder errors are displayed axis-specifically in the control with the error
message "Absolute encoder defective".
The exact type of error is displayed in the "Service number" line in the Service status display
menu. The error number is displayed.
Error numbers are explained in the section "Absolute encoder errors".
Note:
• When the absolute encoder is first switched on, various absolute encoder numbers are
displayed for a period of approx. 10 minutes. This is caused by the back-up battery of the
absolute encoder which only establishes error-free communication with the control after a
certain charge time.
• All absolute encoder errors are transmitted from the absolute encoder to the control on
start-up. It is not possible to acknowledge the absolute encoder errors (e.g. using the
reset key). The control can only be informed that the error has been eliminated after a
renewed POWER ON.
• The specified axis numbers must be consecutive, i.e. no gaps in the numbering are
permitted.
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SINUMERIK 840C (IA)