CLIF-CBUSLC INTERFACE – INSTALLATION & COMMISSIONING INSTRUCTIONS
11
EN1Z-1026GE51
R0417
Table 6. Required slide switch settings
setting
remarks
END DO
NOT
USE!
BIAS DO
NOT
USE!
MID
For C-Bus communication, the switch must be in the
leftmost position.
47 kOHM
47 kOHM
+5V
ISO
GND-1
RS485-1 (+)
RS485-1 (-)
25
26
MID
MID
(MANDATORY!)
BIAS
END
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
Max. cable length (L)
9.6 - 76.8 kbps
1200 m
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.