Galil DMC-1700 Design Examples, Example 1 - System Set-up, Example 2 - Profiled Move, Te X Cr

Again, the system may vibrate if the gain is too high. In this case, reduce KP. Typically, KP should not be greater than KD/4. (Only when the amplifier is configured in the current mode).

Finally, to select KI, start with zero value and increase it gradually. The integrator eliminates the position error, resulting in improved accuracy. Therefore, the response to the instruction

TE X (CR)

becomes zero. As KI is increased, its effect is amplified and it may lead to vibrations. If this occurs, simply reduce KI. Repeat tuning for the Y, Z and W axes.

For a more detailed description of the operation of the PID filter and/or servo system theory, see Chapter 10 - Theory of Operation.

Design Examples

Here are a few examples for tuning and using your controller. These examples have remarks next to each command - these remarks must not be included in the actual program.

Example 1 - System Set-up

This example assigns the system filter parameters, error limits and enables the automatic error shut-off.

Instruction	Interpretation
KP10,10,10,10	Set gains for a,b,c,d (or X,Y,Z,W axes)
KP*=10	Alternate method for setting gain on all axes
KPX=10	Alternate method for setting X (or A) axis gain
KPA=10	Alternate method for setting A (or X) axis gain
KP, 20	Set Y axis gain only

1X80

When using controllers with 5 or more axes, the X,Y,Z and W axes can also be referred to as the A,B,C,D axes.

InstructionInterpretation

OE 1,1,1,1,1,1,1,1	Enable automatic Off on Error function for all axes
ER*=1000	Set error limit for all axes to 1000 counts
KP10,10,10,10,10,10,10,10	Set gains for a,b,c,d,e,f,g,and h axes
KP*=10	Alternate method for setting gain on all axes
KPX=10	Alternate method for setting X (or A) axis gain
KPA=10	Alternate method for setting A (or X) axis gain
KP,,10	Set Z axis gain only
KPZ=10	Alternate method for setting Z axis gain
KPD=10	Alternate method for setting D axis gain
KPH=10	Alternate method for setting H axis gain

Example 2 - Profiled Move

Objective: Rotate the X axis a distance of 10,000 counts at a slew speed of 20,000 counts/sec and an acceleration and deceleration rates of 100,000 counts/s2. In this example, the motor turns and stops:

DMC-1700/1800 Chapter 2 Getting Started • 35