Watlow Electric Gateway & DeviceNet - Manual (Page 20)

RUI/Gateway & DeviceNet TM
Configuration & Ladder Logic Example
Using an Allen-Bradley CompactLogix PLC
Watlow
1241 Bundy Blvd
Winona, MN 55987
Telephone: 507-494-5656
© 2007 Watlow Electric Mfg Co 20
4/08
37. In step 30 it was suggested that the user may want to create user defined data types.
Likewise, in step 31 it was also suggested that the user should create controller tags utilizing
those same user defined data types. The reasoning for this may become more obvious in the
following example. Below, two copy instructions are programmed to send and receive the
implicit assemblies to/from the PLC to the desired EZ-ZONE
®
controls.
38. As can be seen above the controller tags created for inputs from the EZ-ZONE
®
controls to
the PLC was defined as “GTW_Inputs” where the tag created for the outputs from PLC to EZ-
ZONE
®
controls was named “GTW_Outputs”. The ease in programming should now be
apparent. Due to the fact that the user defined data types for both T to O and O to T
assemblies where defined to correlate directly to the specific EZ-ZONE
®
members of choice
the transfer of data between EZ-ZONE
®
controls and the PLC is done without a lot of effort.
Below the two graphics represent both the T to O and O to T assemblies with live data.