4.2.3Precautions when connecting a GOT directly to a PLC CPU in the redundant system without making Q redundant setting

(1)As the GOT monitors exclusively the PLC CPU that is directly connected to, the monitor target cannot be changed in response to the system switching of the redundant system.

To change the target monitor in response to the system switching, change the target of the connection cable between the GOT and PLC CPU to the other PLC CPU, or configure the system using GOTs connected to each

PLC CPU.

(2)In CPU direct connection, when monitoring a PLC CPU in the redundant system, only the PLC CPU that is directly connected to the GOT can be monitored.

(3)When connected to the standby system PLC CPU, the writing of the GOT to a device in the connected PLC CPU is not reflected. Design a monitor screen that disables writing to the standby system.

In the redundant system, the tracking function transfers device data from control system to standby system. When the tracking function is enabled, the device value of the standby system PLC CPU is overwritten by the device value transferred from the control system to the standby system even if the GOT writes to the standby system PLC CPU (Numerical input, Ascii input, Script, Recipe, or others).

 

 

 

 

 

 

 

 

 

CPU direct connection

 

 

 

 

 

 

 

 

 

 

CPU direct connection

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GOT1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GOT2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2) Tracks D100=5 from control

 

 

 

 

 

 

1) Numerically input D100=100

 

 

 

 

 

 

 

 

system to standby system.

 

 

 

 

 

 

 

 

from the GOT.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

module

supplyPower

Q25PRHCPU

 

25-QJ71LP21

QJ71BR11

 

100-QJ71E71

 

QJ61BT11N

 

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supplyPower module

 

Q25PRHCPU

 

 

25-QJ71LP21

QJ71BR11

 

100-QJ71E71

 

QJ61BT11N

 

 

Empty

Standby system

Control system

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(System A)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(System B)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1) D100=100

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MELSECNET/H remote I/O network

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2) D100=5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

supply Power module

 

25-QJ72LP25

 

QJ71C24N

 

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Empty

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

As countermeasures to the above, perform the following.

Display a monitor screen which indicates that "the connected PLC CPU is the standby system" on a GOT when connecting the GOT to the standby system PLC CPU.

To display the specified monitor screen when connecting the GOT to the standby system PLC CPU, use the special relay SM1515 (Control status identification flag) of the PLC CPU.

(When the SM1515 is OFF, the connected PLC CPU is the standby system)

Control the operation of each object by the SM1515, which is set for the operation condition.

For the screen switching device, use a GOT internal device.

If a device of the PLC CPU is used, the Status Observation operation of the GOT may be disabled since the device data of the PLC CPU will is overwritten by the device value transferred with the redundant system tracking function.

1

PREPARATORYFORPROCEDURESMONITORING 2

RANGESETBE

DEVICE CANTHAT 3

RANGEACCESS MONITORINGFOR 4

MONITORTOREDUNTANTSYSTEM HOW 5

CONNECTIONBUS 6

DIRECTTOCONNECTIONCPU 7

LINKCOMPUTER CONNECTION 8

ETHERNETCONNECTION

4. HOW TO MONITOR REDUNTANT SYSTEM

4 - 13

4.2 Direct CPU Connection