WIRING DIAGRAMS
B3000-B Serial Brains User’s Guide
12
WIRING DIAGRAMS
Wiring a B3000-B to a SNAP-PAC-S1 Controller
NOTE: The SNAP-PAC-S1 controller supports only 2-wire RS-485.
Two-wire
Two-wire with interrupt line
TX/RX +
TX/RX –
COM
Pin 1
TX/RX +
TX/RX –
COM
Termination switches, end of cable
IRQ and TX/RX ON; RX OFF
Middle of cable
All switches OFF
Earth GND
1
2
3
ON
1
2
3
ON
Both switches ON
TX/RX +
TX/RX –
COM
Pin 1
TX/RX +
TX/RX –
COM
Earth GND
IRQ +
IRQ –
IRQ +
IRQ –
TX/RX +
TX/RX –
COM
IRQ +
IRQ –
Middle of cable
All switches OFF
1
2
3
ON
1
2
3
ON
Termination switches, end of cable
IRQ and TX/RX ON; RX OFF
Both switches ON
Termination switches, end of cable
IRQ and TX/RX ON; RX OFF
