Edm1 (External Device Monitor); Edm1 Output Signal Specifications - YASKAWA SGD7S Product Manual

11.3

EDM1 (External Device Monitor)

The EDM1 (External Device Monitor) signal is used to monitor failures in the HWBB. Connect
the monitor signal as a feedback signal, e.g., to the Safety Unit.
Note: To meet performance level e (PLe) in EN ISO 13849-1 and SIL3 in IEC 61508, the EDM1 signal must be mon-
itored by the host controller. If the EDM1 signal is not monitored by the host controller, the level will be safety
performance level c (PLc) and SIL1.
• Failure Detection Signal for EDM1 Signal
The relationship between the EDM1, /HWBB1, and /HWBB2 signals is shown below.
Detection of failures in the EDM1 signal circuit can be achieved by using the status of the
/HWBB1, /HWBB2, and EDM1 signals in the following table. A failure can be detected by
checking the failure status, e.g., when the power supply is turned ON.
Signal
/HWBB1 ON
/HWBB2 ON
EDM1 OFF
 The EDM1 signal is not a safety output. Use it only for monitoring for failures.
11.3.1

EDM1 Output Signal Specifications

If an HWBB is requested by turning OFF the two HWBB input signal channels (/HWBB1 and /HWBB2)
when the safety function is operating normally, the EDM1 output signal will be turned ON within 8 ms.
/HWBB1
ON
/HWBB2
(normal operation)
EDM1
Logic
ON OFF
OFF ON
OFF OFF
WARNING
8 ms max.
OFF (motor current shut-OFF request)
OFF

11.3 EDM1 (External Device Monitor)

11.3.1 EDM1 Output Signal Specifications

OFF
OFF
ON
ON
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