Fault Examples With The Safety Remote I/O Module; Input Circuit Troubles And Corrective Actions - Mitsubishi Electric NZ2GFSS2 32D S1 User Manual

10.5

Fault Examples with the Safety Remote I/O Module

Input circuit troubles and corrective actions

An input signal does not turn off.
■Cause
Operation by a switch with LED indicator
Leakage current
(1) Safety remote I/O module
■Action
Connect an appropriate resistor as shown below so that the leakage current flowing into the safety remote I/O module would
fall below the OFF current.
Resistor
(1) Safety remote I/O module
■Calculation example (NZ2GFSS2-32D-S1)
When the 24VDC external power supply of the safety remote I/O module is on and an LED indicator switch that has a leakage
current of 3.0mA at a maximum is connected
Leakage current 3.0mA
(1) Safety remote I/O module
1.
The leakage current through the safety remote I/O module does not satisfy the condition of the OFF current of 0.5mA or
lower. Therefore, connect a resistor as follows:
3.0mA
I = 2.5mA
R
R
2.
To satisfy the condition of the OFF current of the input module (0.5mA or lower), the current through the connected
resistor should be 2.5mA or higher. From the formula below, the connected resistor (R) is lower than or equal to 2.4k.
R × I ≥ Z (Input resistance) × I + V
R R
Z (Input resistance) × I + V
Z ZD
R ≤
I
R
DC input
(1)
DC input
Tn
(1)
Xn
COM-
(1)
Tn
Input resistance 2.0kΩ
I = 0.5mA
z
V = 5V
ZD
Xn
COM-
ZD
2.0 × 0.5 + 5.0
= = 2.4 [kΩ]
2.5
10 TROUBLESHOOTING
10.5 Fault Examples with the Safety Remote I/O Module
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