Honeywell Centra Line CLIF-CBUSLC Installation & Commissioning Instructions page 11

Table 6. Required slide switch settings
setting
END DO NOT USE!
BIAS DO NOT USE!
For C-Bus communication, the switch must be in the
MID
leftmost position.
MID
(MANDATORY!)
RS485-1 (+)
RS485-1 (-)
Fig. 11. RS485-1 three-position slide switch setting MID
RS485 Standard
According to the RS485 standard (TIA/EIA-485: "Electrical
Characteristics of Generators and Receivers for Use in
Balanced Digital Multipoint Systems"), only one driver com-
municating via an RS485 interface may transmit data at a
time. Further, according to U.L. requirements, the RS485
interface may be loaded with a max. of 32 unit loads. A max.
of 29 C-Bus devices may be connected.
IMPORTANT
The cable length affects the baud rate. See Table 7.
Table 7. Baud rate vs. max. cable length for RS485
Baud rate
9.6 - 76.8 kbps
For information on wire gauge, max. permissible cable length,
possible shielding and grounding requirements, and the max.
number of devices which can be connected to a bus, refer to
standard EIA-485.
CLIF-CBUSLC INTERFACE – INSTALLATION & COMMISSIONING INSTRUCTIONS
remarks
+5V
ISO
47 kOHM
25
26
47 kOHM
GND-1
Max. cable length (L)
1200 m
11 EN1Z-1026GE51 R0417