Ladder Logic Elements and Instructions

A Special STAT Instruction

Overview

A special version of the STAT instruction has been developed to support

 

Momentum M1 CPUs. The STAT instruction accesses a specified number of words

 

in a status table in the CPU’s system memory. Here vital diagnostic information

 

regarding the health of the CPU and the I/OBus I/O under its control is posted.

 

From the STAT instruction, you can copy some or all of the status words into a

 

block of registers or a block of contiguous discrete references.

 

This section describes the STAT instruction.

Avoid Discretes

 

We recommend that you do not use discretes in the STAT destination node

 

because of the excessive number required to contain status information.

Specify Length

 

The copy to the STAT block always begins with the first word in the table up to the

 

last word of interest to you. For example, if the status table is 20 words long and

 

you are interested only in the statistics provided in word 11, you need to copy only

 

words 1...11 by specifying a length of 11 in the STAT instruction.

Diagram of STAT

 

The STAT block includes a top node (for destination) and a bottom node (for

Block

length). The STAT block is represented in the following illustration.

Continued on next page

870 USE 101 10 V.2

411

Page 411
Image 411
Schneider Electric Processor Adapter Special Stat Instruction, Avoid Discretes, Specify Length, Diagram of Stat, Block