If the Stepper motor is rated at 2.8A RMS, simply select the corresponding dip switches. In this case On-Off-Off for 2.69A. Is this correct? 2.8A isn’t an option so I’d lean towards the lower.
What determines Pulse/Rev rates? It is arbitrary?
First off, the switch settings appear to be for PEAK power, which as the table header states is RMS * 1.4 (3.92 Amps).
I believe this is the value you use to set the limits.
Lower power is fine, just that the lower torque will reduce your maximum speeds (pulse rate)
The Pulses/rev table is the “native” resolution of your motors (200 is typical) multiplied by the micro stepping factor of your controller. This information should be listed somewhere with your motor and driver board documentation. If not, the goal is to set the Pulse/Rev value so that your controller will know how many pulses it takes to rotate your motor exactly one turn.
This value can be determined in other ways, like telling your machine to move 100mm, then measuring the actual move distance. Adjust accordingly.
If you check out the documentation for your driver/motor combination, these are pretty well explained along with how all these setting interact. These are both pdf files, remove the .txt extension.
DM542T_V4.0.pdf.txt (861.3 KB)
This covers current usage by the motor. Assume you have one of these NEMA motors.
Data-Sheet-Stepper-Motor-Support.pdf.txt (839.0 KB)
Hopefully you can answer your own question as I think you’re up to the technical end. We are here if there is confusion.
I feel the motors were a bit warm when I got my OMTech machine. I found the current values were twice the recommended values. Reduced them to the specified amount from the datasheet and they run barely warm.
This also affects how much acceleration can be applied…
If this is a DIY, there are plenty of us that would 
to see photos 
Your solution and why is always helpful and appreciated.
Good luck
Adjusting current values not only impacts motor temperature but also affects acceleration capabilities. Higher current settings usually allow for faster accelerations, but they come at the cost of increased heat generation. For a DIY project, it’s important to refer to the documentation provided for the specific motor and driver combination, as you’ve rightly suggested. Understanding the interplay between different parameters, such as current, voltage, and acceleration settings, is crucial for achieving the best performance and longevity of the system.
Although nobody pays much attention to the details, the maximum motor current applies with the case at a temperature we civilians regard as exceedingly very much way too hot.
For example, from a Shinano Kenshi SST59D datasheet:
Depending on driver condition, motor may
generate excessive temperature. Recommended
temperature on motor surface is 100 deg C max.
The RMS value applies for stepper motors used in more-or-less constant rotation, which is not the case in our laser cutters. When the motor stops moving for a prolonged time, the current stops changing and the RMS calculation degenerates to DC.
In point of fact, at specific rotation angles the current in both windings will add up to 1.4 times the peak current. If the motor stops at that spot, it’ll get toasty warm rather quickly.
Unless you know a lot more about the specific mechanical loads in your machine, including the torque required to accelerate the hardware, start by derating the current by using the RMS value as the peak value. Then reduce the current to keep the case temperature at a reasonable value, while not reducing it so much that the motors cannot accelerate the machinery as needed.
It seems crude, but it’s about the best we can do with our limited knowledge of what’s going on inside the box.
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