Honeywell EXCEL 5000 OPEN SYSTEM XFL521B Product Data page 22

DISTRIBUTED I/O
Table 11. Doubly-terminated bus specifications.
Cable Type
Belden 85102
Belden 8471
Level IV, 22 AWG
JY (St) Y 2x2x0.8
TIA568A Categ. 5 24AWG, twisted pair
NOTE: The cable types listed above are as recommended
by Echelon® in their FTT-10A User Guide. The
cable recommended by Honeywell is the level IV, 22
AWG, solid core, nonshielded cable. Belden part
numbers are 9H2201504 (plenum) and 9D220150
(non-plenum).
DEVICE
TERMINATION
DEVICE
MODULE
Figure 29. Doubly-terminated bus configuration
(recommended).
Free topology requires only one bus termination and allows a
variety of bus configurations (see Figure 30):
DEVICE
TERMINATION
DEVICE
MODULE
SINGLY TERMINATED
DEVICE
TERMINATION
MODULE
DEVICE
Figure 30. Possible bus configurations
EN0B-0090
Max. bus length
8,900 ft (2,700m)
8,900 ft (2,700m)
4,600 ft (1,400m)
3,000 ft (900m)
3,000 ft (900m)
DEVICE
TERMINATION
DEVICE DEVICE
MODULE
DEVICE
DEVICE DEVICE
DEVICE
DEVICE
STAR
DEVICE
Figure 31. Free topology examples.
The FTT specification includes two components that must be
met for proper system operation. The distance from each
transceiver to all other transceivers and to the termination
must not exceed the maximum node-to-node distance. If
multiple paths exist, the maximum total wire length is the total
amount of wire used.
Table 12. Free topology (singly-terminated)
Cable type
Belden 85102
Belden 8471
Level IV, 22AWG
JY (St) Y 2x2x0.8
TIA568A Category 5
24AWG, twisted pair
IMPORTANT
Do not use different wire types or gauges on the
same L
change in line impedance characteristics would
cause unpredictable reflections on the bus.
22
DEVICE DEVICE
TERMINATION
DEVICE
MODULE
DEVICE DEVICE
LOOP
DEVICE
DEVICE DEVICE
DEVICE
DEVICE
DEVICE
DEVICE
DEVICE
DEVICE
DEVICE
TERMINATION
MODULE
MIXED
specifications.
Maximum node-
to-node distance
1,650 ft (500m)
1,300 ft (400m)
1,300 ft (400m)
1,050 ft (320m)
825 ft (250m)
W network segment. The step
ON ORKS
Maximum total
wire length
1,650 ft (500m)
1,650 ft (500m)
1,650 ft (500m)
1,650 ft (500m)
1,500 ft (450m)