Engineered Automation & Power Solutions

Stacker/Reclaimer Wireless Ethernet Application Note

Application Overview

Engineered Software Products upgraded the woodyard programmable logic controller (PLC) systems for a pulp mill. The system consisted of a material handling PLC, two chip stacker PLCs, each located onboard a respective stacker, and two chip reclaimer PLCs, each located onboard a respective reclaimer. The obsolete PLCs that controlled the process were replaced by Allen Bradley ControlLogix-series PLCs.

Due to the coninual movement of the stackers and reclaimers, it was necessary for the material handling PLC to communicate with the stacker and reclaimer PLCs via wireless communications. The old system had a wireless RS-232 link. That was replaced with a wireless Ethernet link.

Application Highlights

  • Prior to the changeover, a site survey was performed to determine the proper hardware for the application.
  • Radio modems provide internal diagnostic information via Hyperterminal, providing troubleshooting assistance.
  • The wireless Ethernet link provides a means for remote programming and troubleshooting, thereby eliminating the need to troubleshoot the stacker and/or reclaimer PLCs locally.
  • Ethernet provides communications speeds up to ten times faster than the old RS-232 link.
  • Detailed alarm information is transmitted from the stackers and reclaimers to the operator in the control room via the material handling PLCs.
  • The system was designed with the capability for all PLCs to be networked together via Ethernet LAN dedicated to PLC programming.

Application System Architecture

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