Rockwell Automation 1715-OF8I Redundant I/O System User Manual - Manual (Page 94)

94 Rockwell Automation Publication 1715-UM001C-EN-P - March 2014
Chapter 2 Installation Instructions
Recommended Circuits for Analog Inputs
This section describes the layout for analog inputs.
1715-TASIF16 Analog Input Termination Assembly Functional Block Diagram
This is the diagram for the analog input termination assembly.
Figure 44 - 1715-Analog Input Termination Assembly Functional Block
Each input signal is routed through the termination assembly to two input
measurement devices. These devices determine the input status and channel
condition and generate the input data for the controller.
Signal and power isolation circuits separate each input channel from the rest of
the system, thus protecting the system components from field faults.
Module power is produced by the internal isolated power supply from the
24V DC dual redundant system power inputs. The isolated power supply
provides power to the module and is protected by over-voltage and under-voltage
detection circuits. Supply voltage monitoring initiates a warning signal and
Power-off Protection mode when a power failure is detected.
Internal diagnostics, controlled by the adapter module, test the module at routine
intervals of 50…100 ms. An independent watchdog arrangement also monitors
the module operation and provides additional fault containment by activating a
shutdown mechanism when a fault is detected.
Channel 0
Channel 1
Channel 2
Channel 3
Channel 4
Channel 5
Channel 6
Channel 7
Field
Inputs
Termination
Assembly
Dual
Redundant
System
Power
SYS_24V1
SYS_24V2
SYS_OV
Dual Input
Measurement
Device
Isolated
Power
Supply Over/Under
Voltage
Protection PWR
Power
Valid
Isolator
PWR
CMD
RES
PWR
CMD
RES
PWR
CMD
RES
PWR
CMD
RES
PWR
CMD
RES
PWR
CMD
RES
PWR
CMD
RES
Dual Input
Measurement
Device
Isolator
PWR
CMD
RES
PWR
CMD
Input Data
Data Management
FPGA
PWR Power
Valid
SPI
Flash
PMA Commands
PMB Commands
PM Commands
I/O Command Bus
Response Bus
Front Panel
LEDS
I/O Backplane
Input Data
Module Status
Channel Status
32106-M Function Block Diagram
Typical Circuit