INTRODUCTION 
Part. No. 2400M2501_6    Touchpoint Pro 
  17  Technical Handbook 
3.3.10  TPPR Backplane 
The TPPR Backplane is the power and information highway to which all of the TPPR modules are attached. There can be 
several backplanes in larger units, and they are installed within the DIN rail to which the modules are clipped. 
The Backplane is available in four lengths (270 mm, 350 mm, 430 mm, 480 mm) to suit 5, 7, 9 or 10 I/O modules 
respectively, but the choice may be restricted by the size of the selected power supply option and the need to maintain 
adequate cooling space between modules. 
Note: The DIN rail is 430 mm for a standard enclosure or 487 mm for the wide enclosure (10 x I/O) option. 
 
 
 
 
 
 
Figure 21.  TPPR Backplane 
The Power Supply Unit (PSU) plugs into the green socket on the left hand side of the Backplane PCB, and it supplies power 
to the modules via the white connectors. The Ring Coupling Module (RCM) normally sits next to the Power Connector and 
handles all of the bi-directional communication between the CCB and the modules, again via the white connectors. 
3.3.11  Ring Network 
The Ring Coupling Module (RCM) and Input / Output (I/O) modules connect to a dual ring circuit so that they can 
communicate with the CCB through each other and through the RCM. 
This enables fail-safe redundancy because, if one addressable module fails and interrupts the primary circuit, the 
addressable modules on either side of it can still communicate with the CCB via the backup ring circuit (see diagram below), 
and the CCB can identify which module has failed by knowing which addressable modules are still active. 
 
 
 
 
 
 
 
 
 
 
 
Figure 22.  TPPR Controller Typical Schematic 
 
   
Field Device 
Output Modules 
RCM Redundancy 
Module (option) 
TPPR- Activated Field Devices 
Communication Board 
 
(COB) 
Control Centre Board 
 
(CCB)