Rockwell Automation MBB BUS Extender Module - Manual (Page 4)

4 MBB October 2005 – Issue 4
Triguard SC300E
TECHNICAL DESCRIPTION
PHYSICAL
The MBB is a 9U high PCB with integral front panel. A general view is shown in Figure 1-1. DIP
switch SW1 is inactive in the present application.
EXTERNAL CONNECTIONS
Each module is plugged into an extension chassis backplane bus system via two DIN41612
connectors J1 and J2 (Figure 1-1). The extension chassis backplane bus interconnections are
shown in Figure 2-2.
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 2-3. For additional information,
refer to the chassis user manual (Ref no. 008-5097).
Connector J1 links the MBB to the I/O modules and is represented on the rear of the chassis
backplane by Area ‘d’. Area ‘d’ consists of extensions 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 (Section 2.5, Extension
chassis addressing).
The I/O modules interface to three isolated communications buses (shown collectively as the
‘MBB-I/O Bus’ in Figure 2-2), each bus being served by one of the MBBs.
Columns ‘a’ and ‘c’ of connectors J2 link each MBB to the expansion bus via rear backplane
connectors ‘e’.
The same basic chassis is used for both the main chassis and the extension chassis.
The following chassis backplane features are not used in the extension chassis application:
• The inter-processor communications bus (Figure 2-2) and hence Column ‘b’ of
connector J2/backplane connector ‘e’.
• Watchdog timer ‘WDT’ connectors ‘f’ (Figure 2-3)
• Diagnostic serial ports ‘g’ (Figure 2-3)
• Expansion Bus
The main and extension chassis are interconnected by ribbon cables running between
expansion bus connectors ‘e’ on their respective chassis backplanes as shown in Figure 2-1.
A special bus expansion adaptor (ref TBA) is used to effect a 2-into-1 junction at intermediate
points.