Rockwell Automation CS300 Trusted CS300 Bridge Module - Manual (Page 8)

Trusted
TM
CS300 Bridge Module
Issue 01 Apr 08 PD-8162 8
1.2. Power Distribution
Each of the Bridge modules is powered from triple redundant PSUs (situated in a separate chassis)
that support the main I/O chassis with 5V, 12V & +/-20Vdc supplies and up to three CS300 extension
chassis with 12V and +/-20Vdc only.
1.3. Communication Busses
1.3.1. The Trusted
TM
to CS300 Primary Chassis
Communication between the Trusted TM Expander Interface Module and the CS300 Primary Chassis is
via one of a possible four or seven triplicated two-way interface cables. A single backplane connector
card routes the individual links in the cable to the three Bridge modules. Data voting is provided at the
Expander Module Interface to ensure that cable faults are detected.
The link handles the following triplicated signals:
Data
- Serial bi-directional bus.
Control - Bus clocks, module-enables and bus direction control.
Slot - Indicating the CS300 I/O slot position to the Bridge.
Expander Chassis ID - 4 bit Trusted TM chassis address code.
1.3.2. Inter-Module Link (IML)
When returning data for Trusted TM Read requests, I/O Module data received by each Bridge module is
shared with the other two using the serial IML via the backplane. The three sets of data are then
arranged sequentially into the response packet for Trusted
TM . The IML is not used during Write
requests.
1.4. Function
When an I/O access is to be performed, the Trusted TM
TMR Processor issues a command packet to
an Expander Interface Module. The Expander Interface decodes the chassis address and transmits
the packet through an Expander bus to receivers in the 8162 Bridge modules.
For short distances of a few metres, a twisted-pair copper cable is used, whilst on longer runs the
copper cable is connected to three T8312 fibre optic units at each end of three pairs (Tx and Rx) of
fibre optic cable. The Bridge modules, receiving the command signals, decode the packet.
The Bridge modules then implement the read or write access on the CS300 I/O module selected and
return a response packet via the serial expander bus. The packet will contain both data and diagnostic
information.