They run in a servo loop
controlled by field-programmable gate arrays and administered by LinuxCNC (computer numeric control) running on a real-time operating system.
Other compact offerings in B&R's portfolio include the 8WS series, designed for applications that require highly precise synchronization and accurate positioning in limited space, and B&R's Acopos P3 servo drives, which deliver a servo loop
closure rate as fast as 50 I1/4s.
It digitally performs both current loop and servo loop
closures to ensure the highest level of positioning accuracy and performance.
This is called a position servo loop
and typically consists of a PID (proportional, integral, derivative) filter to generate the motor command value.
Like other products in the DMC-30000 series, the DMC-30016 is higher speed than Galil's prior generation single-axis controllers; the 125 microsecond servo loop
update time is twice as fast and the 15 MHz encoder frequency and 3.0 MHz stepper pulse output are 25% faster.
The new controller accommodates position feedback data at rates as high as 10 MHz, and has a servo loop
update time of just 100 microseconds, twice as fast as its predecessor.
Instead of employing 'soil' servo loop
gains to eliminate noise and vibration by de-tuning the system--which is a compromise often faced when retrofitting a drive to an existing installation--users can set up the filters to optimise dynamic performance and minimise settling times.
Jan: Ten years ago, steppers were easier for people because they offered positioning capability without having to close a servo loop
, deal with feedback or shoot PID loops.
This loop filter allows the servo loop
to have very high gain at low frequencies, but stabilizes the loop by limiting the high-frequency gain.
A servo loop
, also called a compensator, has the job of driving the motor to a particular position.
Requiring only an external amplifier to be functional, this advanced motion IC provides profile generation, servo loop
closure, PLC-style signal manipulation, and motor signal generation.
The servo loop
can be closed with the addition of a very small absolute encoder, the AE2-64, with 64 absolute pulses per revolution.