Output Read-Back Function - Mitsubishi Electric NZ2GFSS2 32D S1 User Manual

Output read-back function

This function reads back output results and diagnoses whether the external output signal Y is correctly on or off. The read-
back circuit checks the status of output terminals and diagnoses whether it matches with the output status of the control
program to detect output operation errors in the module. To use this function, setting parameters is not required.
IO24V
External power supply
IO24G
Operation at error detection
When the safety remote I/O module detects an error in an output read-back diagnostic, the error (output read-back error) state
is applied and all output points are turned off. For details on the error state, refer to the following.
Page 138 Error codes related to the safety remote I/O module
• For the NZ2GFSS2-32D-S1, when an error is detected in the input dark test, output dark test, or output
read-back diagnostic, the minor error state is applied to the module. However, when multiple errors are
detected and all I/O points of the module are turned off, the error state of Self-diagnostic error (error code:
0101H) is applied.
• The maximum output voltage in the output OFF state is 1.2V. However, even though the voltage exceeds
1.2V due to a short circuit or failure of the hardware, no error is detected until the voltage exceeds 7V. Thus,
connected devices may turn on although the output of the module is in the OFF state.
Setting method
The parameter setting is not required for the output read-back function.
Output circuit
Safety remote I/O
module
Read-back
circuit
Y0
Output signal
Y1
MC
Load
COM-
Output signal
MC Load
8 FUNCTIONS
8.4 Output Diagnostic Function
8
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