MKS MKSINST IE1000A, Инструкция по эксплуатации

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Chapter Three: Operation 4-20 mA IO 15-pin Interface Operation
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4-20 mA IO Valve Override
The valve override feature enables the control valve to be fully opened (purged) or closed independent of the
setpoint command signal.
For a 4-20 mA IO interface:

To Open the valve, apply 5 to 15 VDC to Pin 12.

To Close the valve, apply -5 to -15 VDC Low to Pin 12 or connect Pin 12 to Power Common.

Normal Setpoint operation occurs when Pin 12 is allowed to float.
4-20 mA IO Valve Command Priority
The MFC executes commands based on a hierarchical command structure. The higher priority command is
Valve Open or Valve Closed, followed by normal Setpoint Control. Therefore, if the flow controller is
operating under Setpoint Control, you can send either a Valve Open command to force the valve to the full
open position or a Valve Closed command to stop flow through the valve while the Setpoint Control signal is
maintained.
When setpoints are applied to both the standard 4-20 mA current input pin and the secondary 0 to 5 V
DC
voltage input pin, the device responds to the signal configured as the primary input signal through the
diagnostics and monitoring interface. As shipped from the factory, the 4-20 mA current input pin is
configured as the primary input signal by default.
Both measurement output signals are active, regardless of which setpoint signal is chosen to control the
device. Use caution if / when making connections to the unused measurement output signal.