Filter
Top Products
2. PLC Processing Program
- 3 -
2. PLC Processing Program
2.1 PLC Processing Program Level and Operation
Table 2.1-1 explains the contents of users PLC processing level and Fig. 2.1-1 shows the timing chart.
Table 2.1-1 PLC processing level
Program name Description (frequency, level, etc.)
High-speed processing
program
This program starts periodically with a time interval of 7.1ms.
This program has the highest level as a program that starts periodically.
It is used in signal processing where high-speed processing is required.
Processing time of this program shall not exceed 0.5ms.
Application example:
Position count control of turret and ATC magazine
Main processing
program (ladder)
This program runs constantly. When one ladder has been executed from
the head to END, the cycle starts again at the head.
7.1ms
High-speed
processing
Main processing
This section is used by the controller.
(Note 1)
(Note 1) The section from the END command to the next scan is done immediately as shown with
the X section. Note that the min. scan time will be 14.2ms.
Fig. 2.1-1 PLC processing program operation timing chart
2.2 User Memory Area Configuration
The user memory area approximate configuration and size are shown below.
Control information
Message data
High-speed processing
Main Processing
P251
P252
Internal information table of User PLC
(The table is automatically generated.)
Program with the ladder language
Programs excepting the main processing are
not necessary.
The program order of initial, high-speed and main
processing is random.
Total 4000 steps
Contact coil
comment data
Max. 256Kbyte from control
information to messages.
User PLC
code area
Data excepting the ladder program
Alarm messages
Operator messages
PLC switches
Load meter
Contact coil comment data, etc.
(Each of them can be stored in two languages.)
Total 127Kbyte