Output Read-Back Function - Mitsubishi Electric MELSEC iQ-R Series User Manual

Output read-back function

This function reads back output results and diagnoses whether the external output signals (NZ2GFS12A2-16DTE: Y0 to Y3,
NZ2GFS12A2-14DT: Y0 to Y1) are correctly output.
When an incorrect output is detected, a minor error occurs. The module will recover from the error by eliminating its cause.
By diagnosing whether the status of output terminals matches with the output data of the safety device, this function detects
output operation errors in the module. To use this function, setting parameters is not required.
• NZ2GFS12A2-16DTE
+24V(L PW)
Safety remote I/O
Load power supply
module
24G(L PW)
• NZ2GFS12A2-14DT
+24V(L PW)
Safety remote I/O
Load power supply
module
24G(L PW)
Operation at error detection
When the safety remote I/O module detects an error in an output read-back function diagnostic, the minor error (output read-
back error) state is applied and all output points are turned off. For details on the minor error state, refer to the following.
Page 95 Error Code List
• When an error is detected in the input dark test and input internal dark test, the minor error state is applied
to the module.
• 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.
Output circuit
Output signal
Read-back
circuit
Output signal
Output signal
Output circuit
Read-back
Output signal
circuit
Y0
MC Load
Y1
MC
Load
24G(L PW)
Y0+
MC
Load MC
Load
Y0-
7.4 Output Diagnostic Function
7
7 FUNCTIONS
59