Siemens sinumerik 840D sl Function Manual page 360

Detailed description
2.7 Extended stop and retract (ESR)
General sources
General sources (NC-external/global or mode group/channel-specific):
• Digital inputs (e.g. on NCU module or terminal box) or the control-internal digital output
• Channel status ($AC_STAT)
• VDI signals
• Access via $A_DBB. This approach is not recommended for time-critical signals, since
• Group messages of a number of alarms ($AC_ALARM_STAT)
Axial sources
• Emergency retraction threshold of the following axis (synchronization difference of
• Drive: The system variable $AA_ESR_STAT[axis] "Status for extended stop and retract"
• Drive: The system variable $AA_ESR_STAT[axis] "Status for extended stop and retract"
Note
If NC-controlled ESR is configured, it takes one IPO cycle to process the alarm reactions
NOREADY and STOPBYALARM. This cycle checks whether the alarm source is for ESR.
The reaction "Trigger ESR" or standard reaction (without ESR) occurs in the next IPO cycle.
Self-resetting alarm 21600 displays this status; the checking time is included in the alarm
response time. You can use $MN_SUPPRESS_ALARM_MASK bit16 to suppress display of
alarm 21600.
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image that can be read back ($A_IN, $A_OUT)
the PLC cycle time is included in the overall time. However, it is an appropriate way for
the PLC to influence the sequence or release of the extended stop and retract function. It
still makes sense to link PLC states, provided that these are powered/controlled
exclusively by the PLC (e.g. EMERGENCY STOP, RESET key, STOP key).
electronic coupling, $VA_EG_SYNCDIFF[following axis])
displays: Bit 3: DC link undervoltage/generator operation)
displays: Bit 4: Generator minimum speed)
Special functions: Axis Couplings and ESR (M3)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0