Document Edition 1.5
Page 7 of 12
Network Communication
The controller communicates on an RS-485 LAN using the BACnet MS/TP protocol. Refer to
Delta Controls
Wiring Guidelines
for further details.
MS/TP (RS-485) Wiring
For detailed information on MS/TP and LINKnet wiring refer to
Delta Controls Wiring Guidelines
.
The proper specified cabling must be used to ensure reliable communications. (22 AWG twisted
pair, 100-120 ohms impedance, 17 pF/ft or lower capacitance, with a braided or aluminum foil
shield.)
Controllers should always be wired together in a daisy-chain fashion. Attempting to connect them
using a starred or bus configuration will cause problems on the network.
Networks with a total length greater than 4000 ft or with more than 50 controllers require a
repeater (RPT-768).
LINKnet networks that have only 1-2 controllers, and have less then 100 ft of cable length do not
require network terminators.
