Rockwell Automation Publication 1715-UM001J-EN-P - December 2020
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Chapter 2 Installation Instructions
1715-IB16D Digital Input Module Functional Block Diagram
Figure 33 - 1715-IB16D 16-channel Module Functional Block Diagram
provides a Function Block Diagram of the 1715 digital input module
illustrating the input circuits, isolation circuits, internal power supplies, and
the input data management by the FPGA. Each input signal is routed through a
termination assembly to two input measurement devices. These devices
determine the input status and channel condition and generate the input data
for the ControlLogix controller.
The digital input module receives commands from the adapter and converts
the channel input data into secure digital data packets. Signal power and
isolation circuits separate out each input channel from the rest of the system
and protect the system components from field faults.
The internal isolated power supply from the 24V DC dual redundant system
power inputs produces module power. The isolated power supply provides
power to the module and is protected by over-voltage and undervoltage
detection circuits. Supply voltage monitoring initiates a warning signal and
Power-off Protection mode when a power failure is detected.
Internal diagnostics test the module every application cycle to see whether
values are within the 1%-value fault band, and if appropriate, report a fault.
An independent watchdog arrangement also monitors the module operation
and provides more fault containment by activating a shutdown mechanism if a
fault is detected. For SIL 2 systems the time to active the shutdown mechanism
can be configured in the CRTL on the SIL 2 Safety tab in them module profile
in RSLogix/Logix Designer. For non-SIL 2 systems it is set at 10 seconds.
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
Typical Circuit