Automatic control function programming manual ladder language

2.3 Structure of a Ladder Module - Elementary Sequences
Structure of an Application
A ladder module is a succession of elementary sequences. The number of sequences in a module is limited to 100.
The sequence is the basic entry and compilation unit. There are three types of elementary sequences:
- the sequence used for entry of a table of numerical constants,
- the sequence used for entry of one of more character strings,
- the sequence used for entry of a network of contacts and coils.
2.4 Elements Common to All Types of Sequences
Each sequence includes the following common elements:
- sequence header,
- grafcet step.
2.5 Table of Constants Sequence
2.5.1 General
This type of sequence contains a data table that is processed by a buffer handling function.
This sequence includes:
- an optional label and an optional comment,
- an optional grafcet step,
- an associated %Vxx.L or %Yxx.L variable that contains the table start address,
- a sequence of numerical values in which each value occupies a long word.
Each table can contain up to 500 values.
The number of tables that a module can contain is limited by the maximum module size and the number of sequences
which must be less than 100.
2.5.2 Using a Table
Tables are accessed by the table start address contained in a %Vxx.L or %Yxx.L variable using functions of the type
cpyb(..), cpyl(..), print(..), etc.
The values of a table can be accessed directly by the pointers (e.g. %Yxx -> n.L).
2.5.3 Initialising a Table
A table is initialised when the monitor loads variable %Vxx.L or %Yxx.L with the table start address.
A table sequence must therefore have been executed once by the system before being able to be used by a ladder
sequence in the programme.
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