User`s manual

Watlow EZ-ZONE™ Communications • 38 • Chapter 3 EtherNet/IP
For example, the screen captures below explain and illustrate how to change a given member for both the
O-to-T and T-to-O assemblies. To change other members within either instance, simply change the instance (1
or 2) and attribute value (1 to 20) in the MSG instruction. For a better understanding of what happens when
the instruction is enabled, take a closer look at the message instruction configuration and its associated tags.
Figure 3.8
In configuring the MSG instruction it is important to use hexidecimal entries for the class, instance and
attribute. In the example below (figure 3.9) the 16th location (attribute 10) of the T-to-O assembly structure
(instance 1) will be changed. Looking at figure 3.6 above you will see that the 16th member of the T-to-O as-
sembly defaults to “Profile Action Request.” Once the configuration is complete, click on the communication
tab and define the path to the PM.
When the MSG instruction above is enabled this member will be overwritten, and the new attribute (state
of digital output 6) will be defined by the class, instance and attribute contained in the source element (see
figure 3.11 below).
Figure 3.9 & 3.10
Figure 3.11
Each member in both the O-to-T and T-to-O assemblies can be changed in this manner. Also, any valid class,
instance and attribute not found in the O-to-T and T-to-O assemblies can be read or written to explicitly us-
ing a rung of logic similar to the example in figure 3.3h