Posted on March 04, 2015 at 19:57Remco,
ST employees seem to know nothing about this product.
I have the same application, a 40 oz*in NEMA 17 motor with a 3 oz*in inertial load and 1 step/second rate, intermittient, then up to 7200 s/s.
It is not possible to achieve that speed range with a fixed power supply on the L6472 board.
The main problem is the supply voltage and that youre probably using too high of a current level, and its the wrong board.
Do this:
1. Use the 6472 and set the Accel - Decel and Run currents equal, and at a very low value like 250 mA. Set the motor voltage to between 8 and 10Vdc for single step, or around 17V for 100 s/s, or choose a motor voltage value based on the V/Hz test to measure phase voltage at the desired step rate. Then choose the minimum operating currents that allows the motor to step. Then add a little current to make it stable.
2. Use the L6470, it is much more advanced than the 6472 and controls phase voltage
and current (it controls phase current through controlling phase voltage unlike the 6472 which is a current limit scheme with fixed motor voltage.)
If the motor voltage is too low in either case, the motor cannot accelerate up to speed, may set an OC alarm and apparently that is what youre seeing.
You can do that, it just takes getting support and ST refuses to support us.
Sad./
