D0 HVAC System Controls Evaluation of Upgrade Options

This engineering note documents three different options for upgrading the Dzero HVAC control system. All three options leave the current field hardware and field devices intact and upgrade the computer control hardware and software. Dzero will be heading into a physics run starting in 2000. This physics run could last several years. The Dzero HVAC system is an integral part of climate control and electronics cooling. The current HVAC control system is based upon a 1985 Johnson Controls System. In order to enter the next long-term physics run with a solid HVAC control system, the current control system needs to be upgraded. This proposal investigates three options: (1) Replacement to the next generation of Johnson Controls Hardware and Software with the Johnson Controls operator interface - FESS; (2) Replacement to the next generation of Johnson Controls Hardware and Software with the FIX32 Operator Interface - FESS/Dzero; and (3) Replacement with a commercially available Programmable Logic Controller (PLC) WITH THE FIX 32 Operator Interface - Dzero