10.6
Fault Examples with the Safety Remote I/O Module
Troubleshooting for input circuit
This section describes the troubleshooting for input circuit.
An input signal does not turn off.
■Cause
• Drive by a switch with LED indicator (test pulse not used)
Leakage current
• Drive by a switch with LED indicator (test pulse used)
Leakage current
■Action
Connect an appropriate resistor as shown below so that a current through the safety remote I/O module may become lower
than the OFF current.
Test pulse
not used
Test pulse
used
For the calculation example of a resistor to be connected, refer to the following.
Page 91 Calculation example
■Calculation example
When the module power supply of the safety remote I/O module is on and a switch with LED indicator that has a leakage
current of 2mA at a maximum is connected
Leakage current of 2mA
24VDC
1.
The OFF current through the safety remote I/O module is more than 1.5mA. Therefore, connect a resistor as shown
below.
2mA
I
= 0.5mA
R
24VDC
Z: Input impedance
Xn
Safety remote I/O module
(negative common)
Tn
24G(PW)
Xn
Safety remote I/O module
(negative common)
Tn
24G(PW)
Xn
Safety remote I/O module
(negative common)
Tn
24G(PW)
Xn
Safety remote I/O module
(negative common)
Tn
24G(PW)
IN
Safety remote I/O module
24G(PW)
IN
I
= 1.5mA
Z
R
Z = 4kΩ
24G(PW)
10 TROUBLESHOOTING
10.6 Fault Examples with the Safety Remote I/O Module
10
91