Wiring Rules and Guidelines for Network Integrations - Johnson Controls - Part No. 24-10050-57 - Gateway/Router

BACnet Router Installation Instructions

Document type
Installation Guide
Document number
Part No. 24-10050-57
Document revision
Revision date
Table 1. MS/TP Bus Rules
Category Rules/Maximums Allowed
General One MS/TP Bus trunk supported per BACnet Router
Only daisy-chained MS/TP devices
Number of MS/TP Devices Supported The BACnet Router supports up to 100 CH-PC series devices total on the MS/TP Bus with no more than two repeaters between a BACnet Router and any device and a maximum of 50 devices between repeaters.
Bus Length 1,500 m (5,000 ft) cable per bus segment without a repeater
4,500 m (15,000 ft) cable from BACnet Router to the farthest MS/TP Bus device (three bus segments of 1,500 m [5,000 ft] each, separated by repeaters)
2,000 m (6,600 ft) between two fiber modems
Cable Type Stranded 0.6 mm (22 AWG) 3-wire twisted, shielded cable is recommended. Stranded 0.6 mm (22 AWG) 4-wire (two twisted-pairs) shielded cable is acceptable.
Note: The + and - bus leads should be a twisted pair. On MS/TP Bus applications using 4-wire (two twisted-pairs) cable, isolate and insulate unused conductor. Refer to the MS/TP Communications Bus for BCPro System Technical Bulletin (LIT-12011908) for more information.
Terminations Two MS/TP Bus devices with EOL switches in the ON position, one at each end of each MS/TP Bus segment
Table 2. BACnet Router Ethernet Network Rules
Category Rules/Maximums Allowed
General Point-to-point star topology with network hubs/switches
Line Length and Type 100 m (330 ft) CAT5 cable
Terminations For 10/100 BaseT, no line terminators allowed
1 If any devices other than CH-PC series BACnet controllers are connected to the MS/TP Bus, the maximum total number of controllers on an MS/TP Bus is reduced to 64. The maximum cable length per bus segment is 1,219 m (4,000 ft), and the maximum total MS/TP Bus length is 3,658 m (12,000 ft).
2 Refer to the MS/TP Communications Bus for BCPro System Technical Bulletin (LIT-12011908) for more information on alternative cable types and lengths.