ProSoft Technology MVI56-BSAPS - Manual (Page 58)

MVI56-BSAPS ♦ ControlLogix Platform Reference
Bristol Babcock Serial Slave Module
Page 58 of 83 ProSoft Technology, Inc.
September 22, 2008
ƒ Local addressing
ƒ 127 nodes from each node at a level
ƒ Communication modes: peer to peer, remote database access (RDB), polled
report by exception (RBE)
ƒ Automatic alarm handling
ƒ 16-bit CRC-CCITT
ƒ Asynchronous communications
ƒ RS-232, RS-422, RS-423, RS-485 multi-drop
ƒ RDB requires data address lookup function
ƒ 4 types of poll messages
ƒ Each node maintains transaction statistics (more than MVI std)
ƒ Each transaction is serialized
ƒ ACK handshaking
ƒ Message priority levels
ƒ Data types: signal by address or name, data arrays (array number, row,
column), select signal data (matches criteria), Physical memory (N/A), input
ports (N/A)
ƒ 3 write command types
ƒ Immediate Response Mode.
5.2.3 General Concepts
The following discussion explains several concepts that are important for
understanding the operation of the MVI56-BSAPS module.
Module Power Up
On power up the module begins performing the following logical functions:
1 Initialize hardware components:
2 Initialize ControlLogix backplane driver.
o
Test and clear all RAM.
o
Initialize the serial communication ports.
3 Read module configuration.
4 Initialize module register space.
5 Enable slave driver on selected ports.
After the module has received the configuration, the module begins receiving and
transmitting messages with BSAP devices on the network.