7-3
7-1 Safe Torque OFF (STO) Function
OMNUC G5-Series AC Servo Drives Users Manual (Built-in MECHATROLINK-II communications type)
7
Safety Function
External Device Monitor (EDM) Output Signal
This is a monitor output signal that is used to monitor the status of safety input signals using
an external device.
Connect a safety equipment, such as a safety controller or a safety sensor, to the external
device monitoring terminal.
Relationship Between Safety Input Signal and EDM Output Signal
Normally when both of the Safety inputs 1 and 2 are off, i.e., when the STO function works for
both safety input circuits, the EDM output is on.
You can detect a failure of the safety input circuit and the EDM output circuit by monitoring all
of the following 4 signal statuses using an external device.
These are the two cases of errors:
Both of the Safety inputs 1 and 2 are off. But the EDM output circuit signal does not become on.
Either or both the Safety inputs 1 or/and 2 are on. But the EDM output circuit signal is on.
The maximum delay time is 6 ms after the safety input signal is input and until the EDM output
signal is output.
Signal name
Symbol
Pin
number
Description
CONTROL mode
Position Speed Torque
Full
closing
EDM output
EDM
CN8-8
• Monitor signal is output to detect
malfunctioning of the safety
function.
* This output signal is not a safety
output.
EDM
CN8-7
Signal name
Symbol
Signal status
Safety input 1
SF1
ON
ON
OFF
OFF
Safety input 2
SF2
ON
OFF
ON
OFF
EDM output
EDM
OFF
OFF
OFF
ON
