Micromod Micro-DCI: 53MC5000 MicroLink - Manual (Page 9)

3.0 MICROLINK NETWORK SIZING
The network’s cable length requirements as well as the communications data load must be esti-
mated for efficient network resource allocation.
3.1 NETWORK DISTANCE
The maximum physical length of a MicroLink network depends on two factors: the data transfer
rate and the quality of the interconnecting cable. Typically it is desirable to operate the MicroLink
network at the highest achievable data transfer rate. Cable should be selected on this basis; how-
ever, to minimize the expense of re-cabling, the potential growth of the network, as well as the pos-
sibility of future network reconfigurations to higher data transfer rates should also be considered.
Table 3-1 shows the recommended maximum cable length for the entire network as a function of
data transfer rate and cable quality. The low performance modular cable is terminated at each end
with RJ11 style connectors that plug directly into a 53MC5000 PCS, a 53SU5000 SUPERVISOR-
PC unit, a PC unit with the 53WS5000 product package installed, or a Communication Interface
Terminal Board (ITB). Modular cable is primarily used for interconnecting nodes within the same
cabinet or panel. For limited distances it provides a very inexpensive yet reliable interconnection.
Modular cable with connectors already installed is available in standard lengths as
listed in Section 7, MicroLink Parts List.
Table 3-1. Recommended Maximum Network Cable Lengths*
Mode Data Rate Transactions
per Second Modular Shielded
Twisted
Pair Shielded
Twin-
Axial
0 2 Mbit/s** 1000 50 (15) 100 (31) 200 (61)
1 1 Mbit/s 500 100 (31) 500 (152) 1000 (305)
2 0.5 Mbit/s 250 200 (61) 1000 (305) 2000 (610)
3 0.25 Mbit/s 125 400 (122) 2000 (610) 4000 (1219)
*End-to-end network cable length = feet (meters).
**A MicroLink Network that has a SUPERVISOR-PC unit or a PC unit with the 53WS5000 product
package installed is restricted to 1 Mbit/s or less.
When longer distance runs are required a higher performance cable is needed. Two higher per-
formance cable types are a good quality shielded twisted pair cable (Belden 9841 or equivalent),
and a high quality shielded twin-axial cable (Belden 9860 or equivalent).
Belden 9841 and 9860 cable
types have been found to be satisfactory
. Both of these cable types must be pur-
chased locally or from the manufacturer. (Transition from cabinet modular cable RJ11 connectors
to the compression terminal block connectors that are required by shielded twisted pair and
shielded twin-axial cables is effected at the Communications ITB [p/n 686B622].)
Section 3. MicroLink Network Sizing
7