Yaskawa Sigma-5 User Manual: Design and Maintenance - Linear Motors - Manual (Page 139)

4.7 Safety Function
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4
Operation
(10) Servo Alarm Output Signal (ALM)
In the HWBB state, the servo alarm output signal (ALM) is not output.
4.7.2 External Device Monitor (EDM1)
The external device monitor (EDM1) functions to monitor failures in the HWBB function. Connect the moni-
tor to feedback signals to the safety unit. The relation of the EDM1, /HWBB1, and /HWBB2 signals is shown
below.
„ Failure Detection Signal for EDM1 Signal
The status of the EDM1 signal indicates if a failure was detected in the EDM1 circuit or not, and is determined
by the status of the /HWBB1 and /HWBB2 signals as shown in this table. If the signal status differs from those
shown here, a failure has occurred in the EDM1 circuit. Failures can be detected if the failure status can be
confirmed, such as when the power supply is turned ON.
Signal
Name
Logic
/HWBB1 ON ON OFF OFF
/HWBB2 ON OFF ON OFF
EDM1 OFF OFF OFF ON
WARNING
The EDM1 signal is not a safety output. Use it only for monitoring a failure.