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
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.