Mitsubishi Electric MELSEC iQ-F FX5U User Manual page 109

■When the input signal cannot be received because the current is insufficient
The current rating for the CPU module in X20 or more and the I/O module is 4 mA.
In some cases, depending on extension devices used, it may not be possible to receive the input signal, due to the insufficient
current. Take the following action in such case.
Input current
Adjusted in accordance
with the connected device
PLC
5.6 k
X
S/S
External resistor
(for input current adjustment)
In the case of capturing high-speed pulses
When capturing pulses of a response frequency of 50 to 200 kHz on input X0 to X7 (FX5U-32M and high-speed pulse input/
output module is X0 to X5.), wire the terminals as stated below.
• The wiring length should be 5 m or less.
• Use shielded twisted-pair cables for connecting cables. Ground the shield of each shielded cable only on the CPU module
side.
• Connect a 1.5 k (1 W or more) bleeder resistance to the input terminal, so that the sum of the load current of the open
collector transistor output on the mating device and the input current of the CPU module is 20 mA or more.
The above-mentioned restrictions are due to specifications of connecting device (encoder etc.).
Please adjust the cable length and load, for connecting device.
Proximity sensor
6
6 WIRING
107
6.5 Input Wiring