Proportional Gain (Pressure)

Default: 1
Range: -32768 to 32767

 

Note: Use positive Feed Forward and Gain values if the pressure increases in the extend direction, and negative values if the pressure increases in the retract direction.

 

The Proportional Gain controls how much drive is generated proportional to the Pressure Error. The Pressure Error is defined as the Target Pressure minus the Actual Pressure. The units on the Proportional Gain is millivolts per 10 units of Pressure Error.

 

The Proportional Drive is defined as follows:

 

image\ebx_-2098825506.gif

 

Or more simply:

image\ebx_-656726146.gif

where pu is pressure units.

 

CAUTION: Increase the Proportional Gain gradually. Excessive gain can cause oscillation that could cause damage or injury.

 

Think about this:

Internally, the motion controller must compare the error between the Target and Actual Pressures with error limits to keep values from overflowing. The error limit is the error at which full drive (10 volts) will occur. This internal error limit is calculated as follows:

Error Limit = 1,000,000 / Proportional Gain

Therefore, if the Gain is set to 100, the Error Limit will be 10,000, which means any error greater than 10,000 will be treated as an error of 10,000 and the Overdrive error bit will be set in the Status word.

 


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