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138
6–1
Alarms and Errors
Whenever the Position Control Unit is powered up or data is transferred into
the Unit, checks are performed to ensure that the data is in proper form and
can be used for operation. If an error exists in speed or positioning action
data at this time, an alarm code is generated. Errors that result in alarms in-
clude BCD errors, out-of-range data, and no-data errors (when required data
is set at 0). An alarm will thus be generated, for example, if the required set-
tings are not made in the DM area of the PC. Operation can be continued
even after an alarm has been generated, however, as long as the data that
generated the alarm is not used. An alarm code begins with a 1 or 2.
If operation is attempted with data for which an alarm has been generated,
an error code will be generated and further operation will not be possible.
Error codes can also be generated during pulse output, e.g., when an emer-
gency stop results from CW limit input. An error code begins with a 5 or 9.
Refer to
Appendix A and Appendix B for specific alarm and error codes.
6–2
Outputs to the IR Area
IR word n+5, bit 03
1: Alarm exists.
IR word n+5, bit 5
1: Error exists.
word n+6
This word contains only the most recent alarm or error code. Several error
and/or alarm codes can be read out in sequence by setting the READ ER-
ROR command bit (bit 05 of IR word n). See
Section 4–5 for details.
6–3
Alarm/Error Indicators
The existence of an alarm or error code is indicated both by the alarm/error
LED on the front panel (see figure below) and by the flags (see above) in the
IR area of the PC.
Front Panel LED
ALARM indicator flashes when an alarm code has
been output and ERROR indicator lights when an
error has occurred.
RUN BUSY
CW
CCW
ALARM
ERROR
NC112
6–4
Error Code Output
When there is more than one error code or alarm code, use READ ERROR
to read the codes in sequence.
Alarms
Errors
Alarm Flag
Error flag
Alarm/Error Codes
Error Code Output