MKS 1253D, Инструкция по эксплуатации

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Chapter One: General Information Introduction
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Chapter One: General Information
Introduction
The MKS Type 153D and Type 1253D “Smart” Throttle Valve Controllers are designed for use
in downstream pressure control applications. Both units work with the Type 253 valve and
consist of the same electronics but differ in packaging. The 153 unit includes a 253 valve (built
into it), a microprocessor, RS-232 communication connections, and driver circuits. The driver
circuits eliminate the need for a separate controller box. The 1253 unit uses the same electronics
as the 153 unit, however, the 253 valve is not enclosed in the unit. This allows you to mount a
253 valve separately from the controller box.
The 153/1253 controller contains a digital pressure/position control algorithm that directs the 253
valve to the proper position for either pressure or position control. The pressure or position set
point may be an external voltage applied to the input connector, or sent as an RS-232 message.
The 153/1253 unit reads the pressure signal used for control applications directly from a pressure
transducer.
Power for the 153/1253 unit can be a single DC supply of +15 to +30 Volts. You can use a
+15 VDC, +24 VDC, or +28 VDC supply. The units require approximately 5 Watts of power.
Note
Use a ± 15 V supply to power the 153/1253 unit if you plan to power
transducers from the 153/1253 unit.
When the controller is turned off, or experiences an unexpected power loss, all calibration
constants and the last valve position are saved in non-volatile memory. Therefore, when you
repower the unit, it will be calibrated and ready for operation.
A switch on the front of the controller allows for off-line operation of the valve for
troubleshooting. Switches inside the controller allow you to select:
•
Baud Rate (1200 or 9600)
•
Parity (Odd, Even)
•
Select Analog or Digital Set Point Input
•
Communications Protocol (Standard or Portable Terminal)