CTI Janus Programmable Automation Controller IOG
45
Cable Length and Termination
For each cable type, there is a maximum cable length. As the figure below indicates, the maximum cable length is
measured from the CPU to the most distant tap. Note that a terminating resistor
must
be installed on the end
terminal blocks.
The maximum trunk length can be doubled by using a “T” topology as show below. Note the location of the
terminating resistors.
The following table designates the maximum trunk lengths for each cable type.
Number of
Terminal Blocks
Maximum Distance
Belden 9182
Belden 9271
Belden 9860
2 - 5
2200 ft (670 m)
1100 ft (335 m)
3300 ft (1006 m)
6
2133 ft (650 m)
1067 ft (325 m)
3200 ft (975 m)
7
2067 ft (630 m)
1033 ft (315 m)
3100 ft (945 m)
8
2000 ft (610 m)
1000 ft (305 m)
3000 ft (914 m)
9
1933 ft (589 m)
967 ft (295 m)
2900 ft (884 m)
10
1827 ft (569 m)
933 ft (284 m)
2800 ft (853 m)
11
1800 ft (548 m)
900 ft (274 m)
2700 ft (823 m)
12
1733 ft (528 m)
867 ft (264 m)
2600 ft (792 m)
13
1677 ft (508 m)
833 ft (254 m)
2500 ft (762 m)
14
1600 ft (488 m)
800 ft (244 m)
2400 ft (732 m)
15
1533 ft (476 m)
767 ft (234 m)
2300 ft (701 m)
16
1400 ft (427 m)
733 ft (223 m)
2200 ft (671 m)
TB
TB
TB
TB = Terminal Block
C
P
U
TB
TB
Terminating Resisto
r
Maximum Trunk Length
TB
TB = Terminal Block
C
P
U
TB
TB
TB
TB
Maximum Trunk Length
TB
TB
Maximum Trunk Length
Terminating Resistor
Terminating Resistor
