Default: 100
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.
Feed Forward is an open loop compensation that is proportional to the rate the Target Pressure is changing. This value is expressed in terms of millivolts per 1,000 Pressure Units per second. Extend Feed Forward drive is added to the output only when the axis is extending. The drive output provided by the Extend Feed Forward is determined as follows:
To set the Feed Forward parameters, try ramping the pressure with very small gains. If the axis lags after this parameter has been set, the feed forward is too small or the system response is too slow. If the axis leads, the feed forward is too large or the system response is too slow.
Note: Because pressure does not necessarily react linearly to the drive output (that is, the same amount of drive does not increase the pressure by the same amount at all positions), it is important to tune the Feed Forwards at the particular pressure ramp that will be used. If you will be ramping the pressure multiple times, you may want to use the 0xD8 and 0xD9 commands to set these parameters between pressure ramps.
Think about this:
On hydraulic systems, the extend and retract feed forward terms will be different by the ratio of the extend and retract surface areas of the position.
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