Rockwell Automation T8442 Trusted TMR Speed Monitor - Manual (Page 13)

Trusted
TM
Module T8442
Issue 8 Apr 10 PD-T8442 13
1.2.3. Speed Field Termination Unit (SFTU)
The Field Termination Unit (FTU) connects the FIU to the field.
The T8442 module FTU is referred to as the SFTU.
The SFTU allows speed input signals and shutdown output signals to be routed from the SFIU to the
field connector. It also converts the 24 Vdc field power supply into dual redundant ±15 Vdc power for
the SOFTA relay current sensors and quad 24 Vdc power for the SFIU relay drivers. It provides dual-
redundant monitoring circuits for relay status, load status, 24 Vdc power status, and ±15 Vdc power
status. A smart-slot link connects the SFTU to the HIU and is used to co-ordinate active and standby
modules during module replacement.
1.2.4. FPU Front Panel Unit (FPU)
The FPU is a common hardware platform used within all Trusted TM 8000 series I/O modules. It
provides voted front panel status indication and module removal detection.
The T8442 module LED indicators provide status information for the following:
Slice A healthy
Slice B healthy
Slice C healthy
Module Active/Standby mode.
Module Educated.
Speed Input Status (x9)
Over-Speed Output Status (x3)
Over-Acceleration Output Status (x3)
1.2.5. T8846 Speed Input Field Termination Assembly (SIFTA)
The T8846 Speed Input Field Termination Assembly (SIFTA) is an integral part of the overall T8442
Speed monitor system. It is DIN rail mounted, containing passive signal conditioning, power distribution
and protection components.
1.2.6. T8891 Speed Output Field Termination Assembly (SOFTA)
The T8891 Speed Output Field Termination Assembly (SOFTA) is an integral part of the overall T8442
Speed monitor system. It is DIN rail mounted, containing two fault tolerant, quad-redundant relay
output channels. Three T8891 units are required for each T8442 Speed Monitor.