CHAPTER 2: QUICK START
SNAP PAC S-Series User’s Guide
21
21
Serial Wiring Diagrams
NOTE: SNAP-PAC-S1 controllers only support 2-wire RS-485.
Wiring SNAP-PAC-S1 Controllers to a SNAP PAC SB-Series Brain
Also see
“SNAP-PAC-S1 and -FM Connectors, Indicators, and Pinouts” on page 53
and
“SNAP-PAC-S1-W Connectors and Indicators (Wired+Wireless)” on page 54
.
TX/RX +
TX/RX –
COM
Two-wire
Pin 1
TX/RX +
TX/RX –
COM
2-wire termination, end of link
Switches 3 & 2 OFF
Switch 1 ON
1 2 3
ON
1 2
3
ON
2-wire, middle of link
All switches OFF
Earth GND
TX/RX +
TX/RX –
COM