Siemens SIMATIC FM 453 Manual page 266

Description of Functions
Monitoring/Error If MD20 = 0 is input, all monitoring functions are active.
Diagnostics
Individual monitoring functions can be inactivated by entering 0 in the desig-
nated bit of MD20.
You can deactivate the error messages using the single function "parking
axis" (see Section 9.3.2).
Table 9-12 Error Diagnostics – Absolute Encoder
Diagnosis
Voltage monitoring Encoder power failure
Error in absolute encoder
Warning
!
Hardware monitoring functions should be skipped only for test purposes,
since positioning errors may destroy the machine.
When voltage monitoring is deactivated and the power supply to the encod-
ers or the FM is switched off, an immediate failure in absolute value signal-
ing can cause drive movements if:
Encoder
See Section 4.5.
Connection
9-66
Cause
Error in protocol for data transfer be-
tween absolute encoder and
FM 453
Cable break
an operating mode other than open-loop control is active
and follow-up mode is deactivated
and the servo enable is activated or not parameterized.
Error Message
Diagnostic interrupt, external channel error
(see Troubleshooting, 11-4)
Diagnostic interrupt, external channel error
(see Troubleshooting, 11-4)
FM 453 Servo Drive / Step Drive Positioning Module
C79000-G7076-C453-01