Learn

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Learn

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Learn adapts the PID controller of the valve to the vacuum system and its operating conditions. Learn must be executed only once during system setup. The Learn routine determines the characteristic of the vacuum system. Based on this, the PID controller is able to run fast and accurate pressure control cycles.

This characteristic depends on various parameters such as chamber volume, conductance and flow regime. Therefore it must be performed with a specific gas flow according to instruction below.

The result of Learn is a pressure versus valve position data table. This table is used to adapt the PID parameters. The data table is stored in the device memory which is power fail save. The data table can be up-/downloaded via ‘Control Performance Analyzer’ software or remote interface. Due to encoding the data may not be interpreted directly.

By an Open, Close, Position or Pressure Control command the routine will be interrupted.

 

Parameter

Description

Bank Selection

Select one of four learn bank to place the result of the learn procedure.

Note: Be sure pressure controller select this learn bank!

Pressure Limit [SFS]

Limit pressure to which pressure the learn shall be executed.

The value is related to the sensor full scale of high sensor.

1.0 means the whole pressure range of the sensors

Open Speed

Define the speed for opening the valve during the learn procedure.

May be necessary to prevent a pump from crashing.

1.0 means full speed

Status

State of the current learn

0: Not Started
1: In Progress
2: Completed Successfully
3: Aborted
4: Failed

Warning Info

Warning of current learn procedure:

Bit 0: Learn is running

Bit 1: Checksum error (learn data corrupt)

Bit 2: Learn procedure terminated by user

Bit 3: Pressure at position open > 50% of pressure limit

Bit 4: Pressure at minimal conductance position < 10 % of pressure limit

Bit 5: Pressure falls while move valve in direction of close

Bit 6: Pressure at open position does not match pressure of previous open

Bit 7: Learn procedure terminated by program

Bit 8: Pressure <= 0 at open position (no gas flow set?)