Rockwell Automation T8449 Trusted TMR 24V dc Valve Monitor Module - 40 Channel - Manual (Page 9)

Trusted
TM
Module T8449
Issue 13 Apr 10 PD-T8449 9
Fig 2 shows a simplified functional block diagram of the Trusted TM 24Vdc Valve Monitor Module.
Figure 2 Functional Block Diagram
1.1. Field Termination Unit (FTU)
The Field Termination Unit (FTU) is the section of the I/O module that connects all three FIUs to a
single field interface. The FTU provides the Group Fail-safe switches and passive components
necessary for signal conditioning, over-voltage protection, and EMI/RFI filtering. When installed in a
Trusted
TM Controller or Expander Chassis, the FTU field connector interconnects to the Field I/O Cable
Assembly attached at the rear of the chassis.
The SmartSlot link is passed from the HIU to the field connections via the FTU. These signals go
directly to the field connector and maintain isolation from the I/O signals on the FTU. The SmartSlot
link is the intelligent connection between active and standby modules for coordination during module
replacement.
1.2. Field Interface Unit (FIU)
The Field Interface Unit (FIU) is the section of the module that contains the specific circuits necessary
to interface to the particular types of field I/O signals. Each module has three FIUs, one per slice. For
the TMR 24Vdc Valve Monitor Module, the FIU contains one stage of the output switch structure for
each of the 40 output channels. Both voltage and current flow are monitored for each output channel.
20 of the output channels are used to control field devices. The remaining 20 are used to monitor the
positional feedback voltages for those field devices. Output channels used for feedback monitoring are
never energized.
The FIU receives isolated power from the HIU for logic. The FIU provides additional power
conditioning for the operational voltages required by the FIU circuitry. An isolated 6.25Mbit/sec serial
link connects each FIU to one of the HIU slices.