Type 683 CommunicaTorr Digital Exhaust Throttle Valve

MKS Instruments, Inc. announces the new Type 683 CommunicaTorr Digital Exhaust Throttle Valve specifically designed for computer-integrated applications, where a simple pressure control system is required. The 683 integrates all control, communication, and driver circuits via a compact "add-on" electronics module onto a standard MKS Type 253 throttle valve assembly, eliminating the need for a separate pressure control electronics module. The throttle valve can operate in either of two modes, flapper position control or pressure control, via a DeviceNet network communications interface. All adjustable setup parameters, run time operation, and diagnostics information are available through the network.

The MKS Type 683 is compatible with the MKS Type CT27 Digital Baratron capacitance manometer to provide all of the components required for a network pressure-control loop. The Type 683 contains an integral digital valve controller with a second-generation control algorithm that drives the system to set point faster than conventional controllers and ensures repeatable process parameters without operator involvement. The loop tuning parameters are completely adjustable to accommodate variations in system parameters, such as time constants, transfer functions of the valve and plumbing, and valve gain. The 683 will also accept standard analog output from traditional Baratron capacitance manometers for closed-loop pressure control and will report pressure back to the host via the DeviceNet link. The valves are available in ISO-KF and MF flange styles in bores up to 100mm.

The features of the 683 valve include intelligent programming that can monitor and control key setup and run time parameters and provide diagnostic information to automate troubleshooting. Pressure, position, or set point limits are programmable, and a patented linear valve transfer characteristic assures smooth linear pressure control. Hard-wired safety interlocks have status indicators and two built-in alarm trip points.

The downstream pressure control technique, chosen most often for critical vacuum processes, such as strip, etch and CVD, opens or closes an exhaust throttle valve to change the conductance to the vacuum pump to achieve and maintain the desired process pressure, independent of the gas inlet flow. Downstream pressure control provides high dynamic range, works with all types of pumps, provides fast response, and is tolerant to most effluent gases.

DeviceNet networks reduce hardwiring and maintenance costs, allow interoperability, provide for noise-free data transmission of critical signals, and can result in significant improvements in process performance and uptime.

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