Rockwell Automation 193-EC4 EC4 Current Monitoring Relay User Manual - Manual (Page 102)

Rockwell Automation Publication 193-UM011A-EN-P - September 2010 103
Logic Controller Application Example with Explicit Messaging Chapter 9
Currently OUT A of the EC4 Current Monitoring Relay is energized as shown
in Bit 2 in Integer_Files[1].
Reading a Group of Parameters using the Status Object Class
(0x0375)
In this example, a Periodic Task has been configured within the L32E to execute
every 1000 ms. In this task, one message instruction will be used to read 25
parameters that include data from the voltage, current, real power, reactive power,
apparent power, and power factor groups using the Status Object Class (included
in firmware revision number 5.01 and higher). The supporting ladder logic was
added to execute a MSG instruction every time this Periodic Task executes.
The Status Object allows a user to define which groups of parameters to read
from a single message instruction. Set up an array of integers to define the list of
attributes (parameter groups) to read back from an overload relay with firmware
revision 5.01 and higher. The list of attributes for the status object is show in
Appendix B.
The data will return in an integer array with the first integer representing the
following information:
• Number of Attributes
• First Attribute Number Being Returned
• First Attribute Number Data Status
• First Attribute Data
• Last Attribute Number Being Returned
• Last Attribute Number Data Status
• Last Attribute Data
Set up the MSG instruction in the Configuration tab to read the list of attributes
(Parameter Groups) by configuring the following fields:
• Message Type:
CIP Generic
• Service Type:
Custom
• Service Code:
0x03 (hex)
• Class: 0x375
(hex)
• Instance: 1
(dec)
• Attribute: 0x00
(hex)
• Source Element:
MSG_Read_Request[0]
• Source Length:
Size of source data (Bytes)
• Destination: MSG_Read_Data