3

Configuring Shared I/O References

Shared I/O data is transferred from the active CPU to the backup CPU each sweep. Reference addresses and ranges must be configured for the data to be transferred. There can be up to 20 Kbytes of input data (%I, %AI) and up to 28 Kbytes of output data (%Q, %AQ, %M, %R) transferred.

Input references should be transferred to the backup unit if the program logic requires identical inputs for the two units. Scanning the same Genius I/O blocks in both units is not sufficient to guarantee that the inputs will be identical every sweep.

When using the GDB Control Strategy, it is necessary to transfer all Genius outputs for redundant blocks. Otherwise, the Genius blocks would drive their outputs from the backup when the Primary PLC was serving as the backup.

Parameter

Default

Range

Description

 

 

 

 

%I Ref Adr

%I00001

00001 to 12288*

Starting address for redundant %I data region. Must

 

 

 

be byte aligned.

 

 

 

 

%I Length

0

0 to 12288*

Bit length of the redundant %I data region. Length

 

 

 

must be a multiple of 8.

 

 

 

 

%Q Ref Adr

%Q00001

00001 to 12288*

Starting address for redundant %Q data region. Must

 

 

 

be byte aligned.

 

 

 

 

%Q Length

0

0 to 12288*

Bit length of the redundant %Q data region. Length

 

 

 

must be a multiple of 8.

 

 

 

 

%M Ref Adr

%M00001

00001 to 12288**

Starting address for redundant %M data region. Must

 

 

 

be byte aligned.

 

 

 

 

%M Length

0

0 to 12288**

Bit length of the redundant %M data region. Length

 

 

 

must be a multiple of 8.

 

 

 

 

%R Ref Adr

%R00001

00001 to %R

Starting address for redundant %R data region.

 

 

configured limit

 

 

 

 

 

%R Length

0

0...%R configured

Word length of the redundant %R data region.

 

 

limit

 

 

 

 

 

%AI Ref Adr

%AI00001

00001 to %AI

Starting address for redundant %AI data region.

 

 

configured limit

 

 

 

 

 

%AI Length

0

0 to %AI

Word length of the redundant %AI data region.

 

 

configured limit

 

 

 

 

 

%AQ Ref Adr

%AQ00001

00001 to %AQ

Starting address for redundant %AQ data region.

 

 

configured limit

 

 

 

 

 

%AQ Length

0

0 to %AQ

Word length of the redundant %AQ data region.

 

 

configured limit

 

 

 

 

 

Limit is 2048 for IC697CGR772; **Limit is 4096 for IC697CGR772

GFK-1527A

Chapter 3 Configuration Requirements

3-3

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Image 36
GE 90-70 manual Configuring Shared I/O References, Parameter Default Range Description