Johnson Controls easyIO FS-20 Quick Start Manual page 8

Input and output terminal wiring
considerations
• Run all low-voltage wiring and cables separate from
high-voltage wiring.
• For all input and output cables, use twisted, insulated,
and stranded copper wires.
• Use shielded cables for input and output cables
that are exposed to high electromagnetic or radio
frequency noise.
• Cable runs over 30 m (100 ft) require an offset in the
input and output software setup.
RS-485 bus terminals
Wire the RS-485 terminals in a daisy-chain configuration.
Use a stranded three-wire twisted and shielded cable
as shown in Figure 19. The three different wires are the
positive bus, the negative bus, and the COM.
You can use the RS-485 positive and negative wires as
sensor actuator (SA) bus +ve and SA bus -ve.
8 FS-20 Quick Start Guide
Figure 19: RS-485 wiring
Callout Description
1 Terminal on the first device
2 Terminal on the daisy-chained device
3 Connection to another device on the RS-485
bus
4 Cable shield connection. You do not need to
ground the cable shield.
5 Connection from another device on the
RS-485 bus