Summa Series Servodrive Product Manual
STO
Document Version: V1.01
(Dec, 2019)
© 2019 ESTUN Automation Co., Ltd. All right reserved.
11-7
11.4
Function Description
11.4.1
EDM (External Device Monitor)
The EDM (External Device Monitor) signal is used to monitor failures in the STO. Connect the monitor
signal as a feedback signal, e.g., to the Safety Function Device.
The relationship among the signals of EDM, HWBB1, and HWBB2 is shown in Table 11-1.
Table 11-1
The relationship among the signals of EDM, HWBB1, and HWBB2
Signal
Logic
HWBB1
ON
ON
OFF
OFF
HWBB2
ON
OFF
ON
OFF
EDM
OFF
OFF
OFF
ON
WARNING
The EDM signal is not a safety output. Use it only for monitoring for failures.
If an STO is requested by turning OFF input signals (HWBB1 and HWBB2) when the safety function is
operating normally, the EDM output signal will be turned ON within 5 milliseconds.
ON
EDM
OFF
OFF
ON
≤
5ms
HWBB1
HWBB2
