SA Bus rules and specifications - Metasys - LIT-12011034 - General System Information - Metasys System - Release 11.0

Each bus supervisor supports one SA Bus (and each SA Bus is a single segment).

The guideline for the maximum total number of devices supported on an SA Bus is 10. The SA bus supervisor provides power for all subordinate devices connected to the SA bus, including up to eight NS network sensors. IOMs and XPMs connected to the SA bus are not powered by the bus supervisor.

SA Buses do not support repeaters. See Table 1 for SA Bus power consumption.

365 m (1,200 ft) maximum bus length

152 m (500 ft) maximum distance between an NS network sensor and the bus supervisor (CGM, CVM, FAC, FEC, or VMA supplying power to the sensor) using bus cable connected to the SA Bus screw terminal blocks

30 m (100 ft) maximum length for network sensors using bus cables connected to the RJ-Style modular jack (6-Pin SA Bus Port)

366 m (1,200 ft) maximum bus length

Screw Terminal Connections: 22 AWG Stranded 4-wire, 2-Twisted Pairs, Shielded Cable for screw terminals.

Modular Jack Connections: 6-Pin RJ-Style Modular Connectors with 24 or 26 AWG Solid 6-Wire, 3 Twisted-Pairs

Each SA bus supervisor has integral (fixed ON) EOL termination, which typically provides sufficient EOL termination on an SA bus. Long SA bus runs or persistent communication problems on an SA bus may require EOL termination at the last device on the SA bus (in addition to the integral EOL termination at the SA bus supervisor).