Knowledge Base

It is important to optimise the Write commands performed by the application, otherwise this may cause problems with:

Communication performance, when the Write commands take time to reach the PLCs.

Saturation, when a List Full message appears in the Event Viewer.

The Supervisor is made up of several managers that exchange data using internal messages. Those messages are stored in a list before treatment.

The communication with PLCs is managed by CIMWAY; its manager number is 4. The real time data base is handled by VAR; its manager number is 5.

Solution for equipement variables

To check the number of Write commands sent to equipment, create a program as follows:

SUB MAIN ()
TRACE(1,4,”1000000″) to start the log.
TRACE(0,4,”1000000″) to stop the log.
END SUB

Example

This is an example of a log for an equipment variable :

09/06/00,17:42:48,5,T,,0, ,9,24 # WriteVar TEST.COMMUNICATION.BIT
09/06/00,17:42:48,4,T,,0, ,9,24 # SimpleWrite 1.NET.EQT1.BIT
09/06/00,17:42:48,4,T,,0, ,9,24 # writemode = 0, nbinfo = 1, rang = 1, 1.NET.EQT1.BIT

Solution for any variables

To check the number of Write commands on any kind of variable, create a program as follows:

SUB MAIN ()
TRACE(1,5,”1000000″) to start the log.
TRACE(0,5,”1000000″) to stop the log.
END SUB

Example

This is an example of a log for an internal variable:

09/06/00,17:43:02,5,T,,0,,9,24 # WriteVar TEST.INTERNAL.BIT