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Functions
Primary and Standby PLC functions
The Primary and Standby PLCs are physically and functionally identical, but their
roles differ according to whether they are in Primary or Standby mode.
Primary Premium PLC
b
Executes the application program in full
b
Updates the inputs and outputs, depending on the selected in-rack architecture on
bus X, on Modbus and/or on Ethernet Modbus/TCP network
b
Communicates with the peripheral devices
b
Sends its data to the Standby PLC and retrieves diagnostic data from the Standby
PLC via the dedicated CPU Sync link
b
Generates its own diagnostic data as well as that of the Hot Standby architecture
Standby Premium PLC
b
Acquires the state of the in-rack I/O on Bus X of the Standby PLC
b
Acquires the image of the Primary PLC inputs (in-rack inputs on bus X, on Modbus
and/or on Ethernet Modbus/TCP network)
b
Executes part of the application program (only 1
st
program section)
b
Updates the image of its outputs depending on execution of the 1
st
program section)
b
Communicates with the peripheral devices
b
Retrieves diagnostic data from the Primary PLC
b
Generates its own diagnostic data as well as that of the Hot Standby architecture
Primary/Standby status management
Failure of one of the following components:
v
Main rack power supply
v
PLC processor
v
“
Monitored” Ethernet Modbus/TCP network module
TSX ETY 4103/5103
automatically triggers a Primary/Standby changeover. For all the other components,
the changeover from Primary to Standby can be customized by the application
program (user-initiated changeover)
Management of shared I/O on the Ethernet Modbus/TCP network
The Primary PLC manages the exchange of the states of the shared I/O on the
Ethernet network (bus or ring type) after a simple configuration operation, with no
need for special programming thanks to the advanced I/O Scanning service.
Only the Primary PLC acquires the physical inputs on the network and controls the
physical outputs on this network.
On each scan, the Standby PLC receives the images of the I/O on the Primary PLC
Ethernet network via the dedicated CPU Sync link. This memory update allows a
smooth changeover from Primary to Standby during the changeover time (products
or devices with maintain state on fallback).
Management of redundant I/O
For the redundant inputs, the sensor data is transmitted to the Primary and Standby
PLCs simultaneously via the input module placed in the racks of each PLC (see
page 4/55).
The output values are only generated by the Primary PLC application processing.
This PLC sends its commands to the corresponding output modules. On each scan,
the Standby PLC receives the Primary PLC output values via the dedicated CPU
Sync link and applies them to its own outputs.
This update allows a smooth changeover from Primary to Standby during the
changeover time (outputs with fallback to state 0).
Services provided by the TSX ETY 4103/5103 Ethernet
Modbus/TCP modules in a Hot Standby architecture
Standard Web services: Rack Viewer and Data Editor
FactoryCast configurable Web services (TSX ETY 5103 only)
User Web pages (8 MB with TSX ETY 5103)
Modbus TCP/IPmessaging
HTTP, FTP, XIP, Telnet
I/O Scanning
NTP time synchronization (with TSX ETY 5103)
SMTP e-mail notification (via Unity Pro function blocks)
Network manager, SNMP agent
Functions
Presentation:
page 4/52
Description:
page 4/53
Architectures:
pages 4/54...
References:
pages 4/60 ...
Modicon Premium automation
platform
Hot Standby system
Unity Pro software
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