YASKAWA GA800 Technical Reference page 308

5.6 Safe Disable Input
Safety Function Status Monitor
The drive Safety monitor output sends a feedback signal about the status of the Safety function. The Safety monitor
output is one of the possible settings available for the MFDO terminals. If there is damage to the Safe Disable circuit,
a controller (PLC or safety relay) must read this signal as an input signal to hold the "Safe Torque Off" status. This
will help verify the condition of the safety circuit. Refer to the manual for the safety device for more information
about the Safety function.
You can use the MFDO function settings to switch the polarity of the Safety monitor output signal. Refer to
5.30 for setting instructions.
Keypad Display
If the two input channels are OFF (Open), the keypad will flash STo [Safe Torque OFF].
If there is damage to the Safe disable circuit or the drive, the keypad will flash SToF [Safe Torque OFF Hardware]
when one input channel is OFF (Open) and the other is ON (Close the circuit). When you use the Safe disable circuit
correctly, the keypad will not show SToF.
If there is damage to the drive, the keypad will show SCF [Safety Circuit Fault] when the drive detects a fault in the
Safe disable circuit. Refer to the chapter on Troubleshooting for more information.
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Validating the Safe Disable Function
After you replace parts or do maintenance on the drive, first complete all necessary wiring to start the drive, then test
the Safe Disable input with these steps. Keep a record of the test results.
1. When the two input channels are OFF (Open), make sure that the keypad flashes STo [Safe Torque OFF], and
make sure that the motor is not running.
2. Monitor the ON/OFF status of the input channels and make sure that MFDO set to the EDM function operates as
shown in Table 5.30.
If one or more of these items are true, the ON/OFF status of the MFDO may not display correctly on the keypad:
• Incorrect parameter settings.
• A problem with an external device.
• The external wiring has a short circuit or is disconnected.
• There is damage to the device.
Find the cause and repair the problem to correctly display the status.
3. Make sure that the EDM signal operates during usual operation as shown in
308
Table 5.30.
YASKAWA SIEPC71061737D GA800 Drive Technical Reference
Table