Emerson E2 Installation And Operation Manual page 21

Instructional Leaflet IL01412009E
Pow-R-Command™ 1000—
breaker control bus communication protocol
Introduction
Eaton's Breaker Control Bus (BCB) communicates
using a sub-set of the Modbus
This protocol is intended to provide a simple
mechanism for systems integrators and OEM
applications to communicate with Eaton
rail drivers. Consult the Modbus protocol
specification (http://www.modbus.org) for
more detailed information on the protocol.
The rail drivers communicate over a multi-drop
twisted pair RS-485 network using RTU formatted
messages at 9600 baud, no parity, 8 data bits,
and 1 stop bit. The maximum packet size including
addressing and CRC is 80 bytes.
Up to 16 Eaton BCBs can be connected to a single
network. Each BCB must have a unique address
from 1 to 16. The address is set with DIP switches
on the BCB itself. Table 1 shows the DIP switch
settings for each address.
Effective October 2012
Supersedes August 2006
Table 1. Device/Settings
Device Address
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Up to 21 EATON BABRSP or GHQRSP-series
remotely operated circuit breakers can be
connected to each BCB. Each breaker is
referenced through a Modbus output coil
register. The first breaker is located nearest
the controller as indicated on Figure 1.
Breaker control bus
protocol.
®
Breaker 1 (Coil 0)
Figure 1. Modbus Output Coil Register
The following Modbus commands are processed
by the Eaton BCB.
Table 2. Modbus Commands
Command
2 (0 x 02 hex)
5 (0 x 05 hex)
17 (0 x 11 hex) Report Slave ID
65 (0 x 41 hex) Device-Specific
The Eaton BCB rails must be powered from
29 Vac control transformer rated at 96 VA. Consult
the BCB Installation Manual for more information.
DIP Switch Settings
00000001
00000010
00000011
00000100
00000101
00000110
00000111
00001000
00001001
00001010
00001011
00001100
00001101
00001110
00001111
00010000
Breaker 2 (Coil 1)
Breaker 21 (Coil 20)
Definition Function
Read 1X Registers Read breaker feedback
status, presence, last
command, and alarm
Write Single Coil Force breaker on/off
Read rail driver information
Eaton-specific commands
(e.g., Device Reset)