Chapter4 Functions; Dual Input Function - Mitsubishi Electric MELSEC Q Series User Manual

4
FUNCTIONS
CHAPTER4
Table 4.1 shows the list of safety relay module functions.
Function

Dual input function

Start-up/off check function
Start-up method selection function
Safety output function
Monitor function
Partial shutdown function with
extension module
4.1 Dual Input Function
This function doubles safety inputs to prevent damage of the safety functions due to a
single failure.
The doubled safety inputs operate after making sure that the internal module, external
devices, and wiring are normal by the start-up/off check function, Briefly, if a module,
external devices or wiring has a failure, the module does not start.
After module start-up, if one safety input does not turn OFF due to a failure, the output is
cut off by turn-OFF of the other safety input.
FUNCTIONS
Table 4.1 Function list
Prevents damage of the safety functions due to a single failure by doubling
inputs.
•Input N type: Dual input with positive common and negative common
•Input P type: Dual input with positive commons
In case of input N type, when between dual inputs shorts, a short occurs
between the power supply and grounding, resulting in power-OFF with
electric fuse.
Checks that status of the safety relay module and external device are normal.
Allows to select the start-up method either auto mode or manual mode with
setting switch.
Prevents incorrect output due to a single failure by doubling safety relay
contacts internally.
Allows to check operating status of the whole safety relay modules including
extension safety relay modules by connecting with the programmable
controller using programming tool.
Allows to shut off only the outputs of certain modules by using safety inputs of
extension module.
COM0 COM1
Safety relay module
Figure 4.1 Dual input wiring
Description
Two inputs
X0 X1
Verification
One signal
4.1 Dual Input Function
1
2
Reference
Section 4.1
3
Section 4.2
Section 4.3
Section 4.4
4
Section 4.5
Section 4.6
5
6
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