Theory Of Operation; Spa Operation; Lon Operation - ABB REC 561 User Manual

1MRK 580 142-XEN
Page 7 - 44

2 Theory of operation

2.1 SPA operation

2.2 LON operation

Remote communication
All remote communication to and from the terminal (including the front
PC port communication) uses either the SPA-bus V 2.4 protocol or the
LonTalk protocol.
The SPA protocol is an ASCII-based protocol for serial communication.
The communication is based on a master-slave principle, where the termi-
nal is a slave, and the PC is the master. Only one master can be applied on
each fibre optic loop. A program is needed in the master computer for
interpretation of the SPA-bus codes, and for translation of the settings sent
to the terminal. This program is called SMS-BASE with the appropriate
SM/REx 5xx-modules.
The LON protocol is specified in the LonTalkProtocol Specification
Version 3 from Echelon Corporation. This protocol is designed for
communication in control networks and is a pier-to-pier protocol
where all the devices connected to the network can communicate with
each other directly. For more information on the bay-to-bay commu-
nication, refer to Event function (1MRK 580 140-XEN) and Com-
mand function (1MRK 580 165-XEN).
ABB Network Partner AB
Version 1.0-00