Rockwell Automation MRB04XM Remote Bus Extender Master Module - Manual (Page 4)

4 MRB04XM October 2005 – Issue 5
Triguard SC300E
TECHNICAL DESCRIPTION
PHYSICAL
The MRB04XM Remote Bus Extender Master Module is a 9U high PCB with integral front
panel. A general view of the main components is shown in Figure 2-1 . DIP switches SW1 and
SW2 are used to set the enable and addresses of up to four remote chassis.
EXTERNAL CONNECTIONS
Each module is plugged into an extension chassis backplane bus system via two DIN41612
connectors J1 and J2 (Figure 2-1 ). The connections to remote chassis are serial links along
fibre-optic cables which plug into ST type transmitter and receiver connections on the front
panel. The top four connectors are the transmitters and the lower four are receivers enabling
two-way communication between the master modules and up to four slave modules in remote
chassis.
CHASSIS BACKPLANE
The signals passing through J1 and J2 are available at the rear of the extension chassis
backplane. The rear backplane connectors are shown in Figure 2-6 . For additional information,
refer to the Chassis user manual (Ref 008-5097).
Connector J1 links the Remote Bus Extender to the I/O modules in the local chassis.
Extensions are provided to the pins of the J1 mating connector (96 pins in three columns ‘a’, ‘b’
and ‘c’). Pins 07 to 10 of columns ‘b’ and ‘c’ are specially extended to enable the installation of
the chassis address setting links (see Figure 2-6 ).
The I/O modules interface to three isolated communications buses (shown collectively as the
‘I/O Bus’ in Figure 2-5 ), each bus being served by one of the Remote Bus Extenders. Columns
‘a’ and ‘c’ of connectors J2 link each Remote Bus Extender to the expansion bus via rear
backplane connectors ‘e’. The same basic chassis is used for the main chassis, the extension
chassis and the remote chassis.
The following chassis backplane features are not used in the extension chassis application at
this time:/
1. The inter-processor communications bus (Figure 2-5 ) and hence Column ‘b’ of
connector J2/backplane connector ‘e’
2. Watchdog timer ‘WDT’ connectors ‘f’ (Figure 2-6 )
3. Diagnostic serial ports ‘g’ (Figure 2-6 ).