Rockwell Automation 1404-M4_M5_M6_M8 Powermonitor 3000 User Manual, PRIOR to Firmware rev. 3.0 - Manual (Page 259)

Publication 1404-UM001D-EN-E - October 2004
Sample Applications C-5
The Write message setup is similar:
MicroLogix 1500 using Modbus
NEW FROM RICH MORGAN