1715-Ob8De Digital Output Module Fbd - Rockwell Automation Allen-Bradley 1715-AENTR User Manual

Chapter 2 Installation Instructions
VFIELD 1
24V
FIELD
VFIELD 2
POWER
VFIELD
OV RTN
Response Bus
Response
Command A,B,C
I/0 Command Bus
I/0 Backplane
SYS_24V1
Dual
SYS_24V2
Redundant
System
SYS_OV
Power
Termination
Assembly
82

1715-OB8DE Digital Output Module FBD

Figure 38 - 1715-OB8DE Functional Bock Diagram (FBD)
Combined Power Feed
Power
PWR Feed Combiner Drives
Combiner
SPI
Flash
Response
Data Management
Isolated
& Output Switch
Backplane
Control A
Interface
Command
PWR Power
PWR Power
Valid
Command
Data Management
& Output Switch
Control B
Response
Isolated PWR
Over/Under
Power
Voltage
Power
Supply
Protection
Valid
See Figure 38. Two independent output switch control units control the field
output channel. The field output circuitry is galvanically isolated from the
processor input commands and response lines by an isolated interface circuit.
This architecture helps protect the system processors from faults in the output
control circuits of the module and possible field device faults.
The internal isolated power supply produces module power, which the dual
redundant system power inputs supply. Over- and undervoltage protection is
applied to the module internal power supply outputs.
Command packets are received from the processor module via the EtherNet/IP
network. The output switch control units decode and vote the output data that
is addressed to them and set the output FET switches accordingly. The output
voltages are produced from the 24V DC field power input voltages by a power
combiner circuit. Each output channel has a pair of FET switches arranged in a
series that are independently controlled. Load current and voltage monitoring
is provided for each switch. Output channel protection makes sure that the
output circuit is switched off when the channel load current exceeds a safe
limit.
Rockwell Automation Publication 1715-UM001J-EN-P - December 2020
IMON A
IMON B
VREF
Output Control
Valid
Output Control
VMON A
Reverse Voltage
Blocking
Channel Module
Status Status
VMON B
VREF
LED Array
Termination
Assembly
Front Panel
Transient
Suppression
CH0 CH7
32107 M1