Mobile Workers Embrace Wireless

Ergon Refining Deploys Mobile Operator Stations Enabled by Wireless Networking to Speed Up Turnaround

By Steve Giddens, Senior Systems Analyst, Ergon Refining

We recently deployed mobile operator stations enabled by wireless networking to speed up turnaround at our plant in Vicksburg, Miss. We saved 60% on labor or more than 1,400 hours worth $187,000.

Our mobile worker project started with buying two Panasonic Toughbook laptop PCs and then connecting them to the plant's DeltaV DCS via four wireless access points and 61 wireless components. We wanted the laptops to work as complete DeltaV operating stations, so one person in the valve area could ask for a valve to be stroked and collect the signal right there.

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Carried out this past January and February, the project had two main objectives: to perform a standard four-to-six-year maintenance turnaround of our hydrogen gas plant and propane distillation asphalt (PDA) plant, which consists of servicing or replacing about 130 valves; and to commission, site-accept and loop-check our crude Hydrogen Processing Unit 2 after migrating it to DeltaV and Emerson's CHARMs electronic marshalling and I/O components. This project included five cabinets, each with two CHARMs I/O carriers (CIOCs) and 96 channels for a total of 550 loops.

The plan involved several primary steps:

• Preconfigure and factory acceptance test (FAT) applicable hardware

• Conduct a site survey

• Finalize locations for access points (APs)

• Optimize AP locations based on available networking infrastructure

• Complete temporary device installations

• Set up and start DeltaV's Mobile Worker program

• Begin to realize initial benefits

• Procure added equipment and ship new hardware to Ergon for final installation.

We also planned to turn the Toughbooks into DeltaV stations by using the remote desktop protocol (RDP) or a remote access service (RAS) server to provide redundancy, access to multiple DeltaV DCSs, and automated disconnect/reconnect with visual feedback. As a result, RAS was implemented on the two laptops' Pro+ sections; a remote node was created in Ergon's DeltaV Explorer software; DeltaV was implemented on the laptops; and a license was assigned to them.

The main equipment used in Ergon's mobile worker project include the two Model CF-19 Toughbooks, which are intrinsically safe, water- and shock-resistant PCs with touchscreen functions. Meanwhile, the AP functions are performed by Cisco 1552 Series outdoor access points, which are Class I, Div 2-rated as explosion-proof, while the plant's WLAN controller is a Cisco 2504 wireless access point. The laptops communicate at 2.4 GHz, while the APs run at 5 GHz, and the overall WPN uses IEEE 802.11an Wi-Fi.

The APs and other wireless devices are secured by the Control and Provisioning of Wireless Access Points (CAPWAP) protocol in Cisco's components. As a result, mobile workers using the Toughbooks and DeltaV are protected because their and the controllers' data is encrypted in a CAPWAP tunnel function that monitors the WPN and disallows any unauthorized communications. Ergon's WPN also uses WPA2 passwords, authentication and security methods, as well as 128-bit encryption of its data.

We initially bought the DeltaV license, used a Cisco wireless router to help build the system, and made sure it was feasible by first bringing up the mobile worker in our conference room. After building a little confidence there, we began implementing Cisco and Emerson radios in other field locations. Our resulting WPN includes three main sections:

• Mesh access points that communicate among themselves and with the wired network using wireless connections over the 802.11a/n radio backhaul. They also provide client access on 802.11b/g/n radios

• A wireless LAN controller that provides centralized control of the APs

• An optional network control system that provides a visualized system view of the network for RF planning and management.

In the future, we might add other devices and capabilities to its WPN. We might add another AP to the PDA or to the terminal area. We're also talking about expanding the WPN into other assets and applications.