General

Quantum PLCs have a specific section management system. It applies to stations with remote inputs/outputs.

These stations are used with following RIO modules:

  • 140 CRA 931 00

  • 140 CRA 932 00

This system allows remote inputs/outputs to be updated on sections with optimum response times (without waiting for the entire task cycle before updating the inputs/outputs).

Operation

The following diagram shows the IO phases when 5 drops are associated to client task sections.

%Ii inputs of drop No. i

%Qi outputs of drop No. i

i drop number

Description

Phase

Description

1

Request to update:

  • the inputs of the first drop (i=1)

  • the outputs of the last drop (i=5)

2

Processing the program

3

  • Updating the inputs of the first drop (i=1)

  • Request to update the inputs of the second drop (i=2)

4

Request to update:

  • the inputs of the third drop (i=3)

  • the outputs of the first drop (i=1)

5

Request to update:

  • the inputs of the fourth drop (i=4)

  • the outputs of the second drop (i=2)

6

Request to update:

  • the inputs of the last drop (i=5)

  • the outputs of the third drop (i=3)

7

Request to update the outputs of the fourth drop (i=4)

Adjustment of the Drop Hold-Up Time Value

In order for the remote outputs to be correctly updated and avoid fallback values to be applied, the drop hold-up time must be set to at least twice the mast task cycle time. Therefore the default value, 300 ms, must be changed if the MAST period is set to the maximum value, 255 ms. The adjustment of the Drop Hold-Up time must be done on all configured drops.