Filter
Top Products
2-3SectionWiring
21
Note The Hood (FG) is internally connected to the ground terminal (GR) on the Power
Supply Unit. Therefore, FG is grounded by grounding the ground terminal (GR)
on the Power Supply Unit. Although there is conductivity between the Hood (FG)
and pin 1 (FG), connect the Hood (FG) to the shield because the Hood (FG) has
smaller contact resistance with the shield than pin 1 (FG), and thus provides bet-
ter noise resistance.
Serial Communications Board
Power Supply Unit
Hood and GR are
internally connected.
Ground to 100 Ω or less Grounding the GR terminal
grounds the Hood (FG).
2-3-6 Recommended RS-422A/485 Wiring Examples
Recommended RS-422A/485 Cable
We recommend the following wiring methods to ensure quality transmissions for
RS-422A/485 communications.
1, 2, 3... 1. Always use shielded twisted-pair cables for the communications cables.
Model Manufacturer
CO-HC-ESV-3Px7/0.2 Hirakawa Hewtech Corp.
2. Connect the shield of the communications cable to the Hood (FG) of the
RS-422A/485 connector on the Serial Communications Board. At the same
time, ground the ground (GR) terminal of the Power Supply Unit to 100 Ω or
less.
Note Always ground the shield only at the Board end. Grounding both ends of the
shield may damage the device due to the potential difference between the
ground terminals.
Connection examples are shown below.
2-Wire Connections
Serial Communications
Board
Remote device
Shield
Hood
Pin
Signal
Signal