C-Bus; C-Bus Termination; Cable Specification; C-Bus Extension By Using Repeaters - Honeywell Excel 50 Installation Instructions Manual

EXCEL 50 INSTALLATION INSTRUCTIONS

C-Bus

4 5 6
Fig. 37. C-Bus connection and LEDs
Up to 30 controllers can communicate with one another and
the Excel Building Supervisor PC (XBS) via the C-Bus.
Instead of an Excel 500/600 Controller, other C-Bus-
compatible components can also be connected (Excel IRC
Multicontroller; Excel EMC; Modem Device XM 100A).

C-Bus Termination

Fig. 38. DIP Switch settings for C-bus
The application module is equipped with a DIP switch for the
C-Bus to set the bus termination appropriate for the com-
munication speed.
Table 17. DIP switch settings for C-bus termination
DIP switch communication
setting speed (max.)
up 9.6 Kbaud
middle 76.8 Kbaud
down 76.8 Kbaud
NOTE: Modules listed in Compatibility column are used in
Excel 20/100B/500/600 Controllers.
NOTE: The controllers with the termination must be switched
ON prior to the controllers in the middle of the C-Bus.
EN1B-0101GE51 R1105D
LEDs
POWER, GRN
RESERVED
C-BUS TxD, YEL
C-BUS RxD, YEL
RESERVED
C-BUS
TERMINATION
SWITCH
C-BUS
controller compati-
location bility
XD505A,
-
XL20XD
XD508,
middle of bus
XL20XD508
beginning or XD508,
end of bus XL20XD508
The C-Bus may not work if the controllers with
termination are switched OFF.

Cable Specification

The max. cable length is 4,000 ft (1,200 m). There are
regional differences as to whether shielded or unshielded
cable must/can be used.
IMPORTANT
In Europe, only shielded cable is permitted while in
the US, shielded or unshielded cable can be used.
Inside the cabinet: J-Y-(ST)Y 2 x 2 x 0.8
Outside the cabinet: A-Y-(ST) 2 x 2 x 0.8
In principle, data transmitting cables should be shielded in
case of RFI.
Table 18 summarizes cable types and gives selection
guidance. Note that baud rate and max. bus length are
related to each other.
Table 18. C-Bus cable types
cable type description
J-Y-(ST)Y shielded,
2 x 2 x 0.8 twisted pair
A-Y-(ST)Y shielded,
2 x 2 x 0.8 twisted pair
unshielded,
AK 3702
twisted pair
AK 3740A shielded
Belden 9842 twisted pair
Belden 9841 shielded
unshielded,
AK 3702
twisted pair
AK 3740A shielded
Each end of the shield on the C-Bus should be connected to
the shield terminal of the respective device. Do not connect it
to the cabinet ground or any other ground points.

C-Bus Extension by Using Repeaters

The C-Bus length can be extended by using repeaters. Each
repeater extends the bus length by 4,000 ft (1,200 m).
For the US the repeater is available either with or without
housing. In Europe, only the version with housing is allowed.
Table 19. Order no. for repeaters
description US order no.
without housing 14507324-001
with housing 14507324-002
20
recommended for
Europe
Inside cabinet
Europe
Outside cabinet
US
not approved for Europe
US (low-cost)
not approved for Europe
Europe
US also possible
US
US
not approved for Europe
US (low-cost)
not approved for Europe
European order no.
-
XD 509