User manual

Publication 1734-UM015A-EN-E - November 2009
80 DeviceLogix Capabilities
Messaging
There are certain parameters that you may want to SET or READ from the
module that are not part of the I/O Assemblies. Those parameters are still
available through messaging.
This section contains advanced user information. You should understand the
CIP object model and be familiar with the terms Service, Class, Instance, and
Attribute.
This section discusses how to SET and READ information from the Timer
and Counter function blocks and how to enable and disable logic with the
Logic Supervisor Object.
The first thing that is important to know is that each function block has a
handle or an instance number. This instance number is assigned by the editor,
it can be found in the upper left corner of the function block.
The instance number can change if you edit the program. It may also be
different from module to module – be very careful to verify the instance
number before using messaging.
To access the information, you need the “address” of that information. The
address is made up of the Class Code, the instance (as discussed above), and
the attribute.
Function block instances