Bacnet Ms/Tp - Roberts Gorden CORAYVAC Installation Manual

12.2 BACnet MS/TP

BACnet MS/TP is a token passing protocol. MS
stands for Master-Slave and the TP stands for Token
Passing. Each controller on the network has the ability
to hear the broadcast of any other device on the
network.
The speed of an MS/TP network ranges from 9600
bps to 76.8 kbps. There are two different ways to
connect I/O Pro 812u to BACnet MS/TP.
12.2.1 To set up the Modulating Controller for
BACnet MS/TP on Port 1
1. Turn off power to control board.
2. Using the rotary switches, set the controller's
address. See Page 40, Section 5.4.
3. Set the Dip switches 4 and 5 for the proper com-
munication speed. (baud rate).
4. Set the DIP switch number 3 off.
5. Set the DIP switches number 6, 7 and 8 off.
6. Connect the communication cable to Port 1, (be
careful for polarity).
7. Set the Port 1, jumper to 485 setting.
Note
• A dedicated 24 AWG to 18 AWG twisted pair wire
(EIA-485)
• 2000' (610 m) for 76.8 kbps
• 3000' (914.4 m) for 9600 bps, 19.2 or 38.4 kbps,
before needing a Repeater
• Devices should be daisy chained and not star
wired
• If the controller is at either end of a network seg-
ment, connect a BT485 Terminating Resistor (P/N
10061018) to the I/O Pro 812u.
• Use the same polarity throughout the network
segment.
8. Turn on power to control board.
9. Set the correct network number to the unique
SECTION 12: I
NTEGRATION WITH
BACnet MS/TP network on the touch screen.
10. Set the unique BACnet Device Instance number
on touch screen.
12.2.2 To set up the Modulating Controller for
BACnet MS/TP on Port 2a
1. Turn off power to control board.
2. Using the rotary switches, set the controller's
address. See Page 36, Figure 19.
3. Set the Dip switches 4 and 5 for the proper com-
munication speed (baud rate).
4. Set the DIP switch number 3 on for port 2a.
5. Set the DIP switches number 6, 7 and 8 off.
6. Connect the communication cable to Port 2a, (be
careful about Polarity).
B M S (BMS)
UILDING ANAGEMENT YSTEM
91