CHAPTER 3: WIRING
B3000-B Serial Brains User’s Guide
15
Wiring the Brain to a PCI-AC48 Adapter Card in a PC
NOTE: Check the default termination and bias on the PCI-AC48 and make certain they are set appropriately for the
network. Termination should be at each end of the RS-485 cable, and biasing should be at one location only, typically
at the host device, which would be the PCI-AC48 in this case.
NOTE: For system architecture drawings using a PCI-AC48 adapter card in a PC, see form 787, the B3000 Brain Data
Sheet.
Two-wire
Two-wire with interrupt line
TX/RX +
TX/RX –
COM
Pin 1
TX/RX +
TX/RX –
COM
Earth GND
PCI-AC48 adapter card in PC
Port A
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
TX/RX +
TX/RX –
COM
Pin 1
TX/RX +
TX/RX –
COM
PCI-AC48 adapter card in PC
IRQ +
IRQ –
Earth GND
Port A
IRQ +
IRQ –
Termination switches, end of cable
IRQ and TX/RX ON; RX OFF
Middle of cable
All switches OFF
1
2
3
ON
1
2
3
ON
