IIIMULTIPORT ELECTRONIC CONTROLLER
A.INTRODUCTION
The Bettis Multiport Electronic Controller (MEC) consists of a motor, Switchpak model SW20N, optional local control station and position display. It is a microcontroller based system developed to control and monitor status of the Multiport Selector Valve. It provides improved accuracy, eliminates mechanical adjustment of cams, and allows digital communication with one or more Multiport Valves over a single cable.
B.TECHNICAL DESCRIPTION
The MEC uses an optical absolute encoder to read the position of the valve into a 8 bit microcontroller. The encoder resolution is 1024 readable positions within the 360b rotation of the valve which results in the plug position being monitored to 0.35b accuracy. The microcontroller controls the motor on/off relay, and the optional digital display, with input from an external host device (computer, RTU or PLC) via a digital communication connection. The inputs from the optional local control station (switch position and pushbutton sense) are also connected to the microcontroller. The microcontroller utilizes a memory chip (EEPROM) which retains the home port setting, and ASCII text message for the valve, even during power failure.
C.ELECTRONIC CONTROLLER SPECIFICATIONS
INPUT VOLTAGE OPTIONS: | 1. | 120 VAC (50 - 60 Hz) | USES SOLID STATE AC RELAY AND |
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| TRANSFORMER |
| 2. | 24 VDC | USES SOLID STATE DC RELAY AND |
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| TRANSFORMER IF REQUIRED |
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BOARD INPUT VOLTAGE: | 8 - 30 VDC OR 9 - 20 VAC |
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BOARD INPUT CURRENT: | 0.5 AMP MAXIMUM |
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BOARD | CONFORMAL COATED |
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| LIGHTING PROTECTED |
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FUSE: | 1 AMP TIME DELAY |
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TEMPERATURE RATING: |
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SHOCK AND VIBRATION: | 10 G's |
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HUMIDITY: | 98% WITHOUT CONDENSATION |
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PROTOCOLS: | 1. | ASCII BASED | CPU CHIP LABELLED "STD" |
| 2. | MODBUS RTU | CPU CHIP LABELLED "MODBUS" |
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