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Use of Thin Clients in an Industrial Environment. Foxboro Southeast User’s Group Birmingham, Al February 10-11, 2009 Walter Conner Senior Plant Engineer. Definition. Network computer without long term storage devices, which typically rely on a server for application processing
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Use of Thin Clients in an Industrial Environment Foxboro Southeast User’s Group Birmingham, Al February 10-11, 2009 Walter Conner Senior Plant Engineer
Definition Network computer without long term storage devices, which typically rely on a server for application processing Manufacturers include HP, WYSE, NCD and others
Quick History • Part of a control board modification project • First used as a replacement for hard panel annunciators in Solaris platform with no operator interaction • Linux based OS. Single head device using telnet as communication protocol • Used existing FoxView licenses • Great reliability, easy to use and configure
History (cont’d) • Migration to MESH required change to Windows XP for workstations, but you can use Linux, XPe or CE as thin client OS. • Involved Foxboro technical personnel to evaluate use of thin client technology • Plant decision to use thin client as a control screen and alarm screen with the MESH upgrade
Advantages • Runs minimal software on the thin client (web browser, remote desktop, etc) Most applications reside on the server. • Easy to secure. Device comes in a locked down environment from the factory. Device has some security software installed that can be configured for your site. • Low cost ~ $ 500 per device for Windows XPe version, less for LINUX or Windows CE
Advantages – Cont’d • No moving parts, so it operates in dirty environments well • Low power consumption ~50 watts per device • Updates to the server updates all connecting thin clients
Advantages – Cont’d • After one device was configured, a custom image was made and loaded onto the other clients. • After the image is restored, it takes minimal steps to configure device and get it ready for operation.
Disadvantages: • Required a private network to be managed separate from Foxboro MESH network • Relies on a server for processing so redundant servers were needed for mission critical applications • Steep learning curve about the thin client device
Operator workstations • Dedicated for one purpose – access to control system displays for monitoring and control • Workstations were needed in more than one place – control room, FGD absorber area, ammonia storage area, checkout, etc. • WPs were not used for data logging – this task is typically performed on server
Installation • Upgraded server system • Use of Windows terminal services requires a Microsoft license • Additional FoxView licenses from Foxboro • Additional memory requirements because all processing is on the server box • RAID 5 drive system for high reliability
Installation • Old system contained 3-AWs and 7-WPs and 8 thin clients for alarm screens • New system is a hybrid system of Foxboro equipment and some thin client equipment • Some Foxboro AWs - 7 • Operator stations - 4 • Engineering station - 1 • Thin client servers - 2 • Some thin clients - 8 • Thin client count includes 4 alarm screens and 4 operator interfaces • Alarm screens do not have keyboard or mouse and are not accessible by the operator
Issues • Functionality of the thin clients required securing the device better - this does take some time and expertise !! I requested help from our IT people as they had someone in house that knew what they were and had some experience with them. • Some custom scripts had to be written to minimize operator interaction. i.e Distribute load between servers, launch specific display • UPS power for operation during trip events • Private network requires rugged design ( don’t use cheap devices )