Honeywell EXCEL 5000 OPEN SYSTEM XFL521B - Page 23

DISTRIBUTED I/O
23 EN0B-0090
Examples of free topology schemes (1 allowed, 2 not
allowed) for cable JY (St) Y 2x2x0.8 are shown below.
Device
Device
Device
CPU
Term in at ion
module
ALLOWED
Node-to-node = 656 ft (200m)
Total wire length = 328 ft (400m)
NOT ALLOWED
Node-to-node = 1287 ft (400m)
Total wire length = 1640 ft (500m)
Device
656 ft
(200m)
656 ft
(200m)
Device
Device
Term in at ion
module
328 ft
(100m)
328 ft
(100m)
328 ft (100m)
328 ft (100m)
328 ft (100m)
Figure 32. Free topology examples (max. node-to-node
320 m, max. wire length 500m)
NOT ALLOWED
Node-to-node = 656 ft (200m)
Total wire len
g
th = 1969 ft
(
600m
)
Ter minat io n
module
328 ft
(100m)
328 ft
(100m)
Device Device
Device
Device
Device
656 ft
(200m)
Figure 33. Additional free topology example (max. node-
to-node: 320 m, max. wire length: 500 m)
NOTE: In the event that the limit on the total wire length is
exceeded, then FTT physical layer repeaters
(FTT 10A) can be added to interconnect segments
and increase the overall length by an amount equal
to the original specification for that cable type and
bus type for each repeater used. For example,
adding repeaters for a doubly-terminated bus using
JY (St) Y 2x2x0.8 cable increases the maximum
length 3000 ft (900m) for each repeater.
LONWORKS Bus Termination
One or two Termination Modules, part no. 209541B, are re-
quired for a L
ONWORKS bus with FTT devices on it, de-
pending upon the configuration. The maximum lengths des-
cribed in "L
ONWORKS Network Interface" must be adhered to
for either a daisy chain or free topology L
ONWORKS bus
layout. See Figure 34 and Figure 35 for connection details for
the 2095401B Termination Module.
Figure 34. Termination Module connections for doubly-
terminated FTT network.
Figure 35. Termination Module connections for a singly-
terminated FTT network.