Applied Motion STR4 - Manual (Page 23)

23
STR4/8 Hardware Manual 920-0030J
5/12/2015
Step 7: Step Pulse Noise Filter
Just when you thought there couldn’t be any more to know about step signals, we present one
more setting for your consideration. Electrical noise can affect the STEP signal in a negative way,
causing the drive to think that one step pulse is two or more pulses. This results in extra motion
and inaccurate motor and load positioning. To combat this problem, the STR drives include a
digital noise filter on the STEP and DIR inputs. The default factory setting of this filter is150 kHz,
which works well for most applications.
However, as discussed in Step 5, if you are operating the STR at a high number of steps/rev and
at high motor speeds, you will be commanding the drive at step rates above 150 kHz. In such
cases, you should remove the cover and move jumper S4 from the 150 kHz position (1-3) to
the 2 MHz position (1-2) as shown below.
Your maximum pulse rate will be the highest motor speed times the steps/rev. For example, 40
revs/second at 20,000 steps/rev is 40 x 20,000 = 800 kHz. Please consider this when deciding if
you must increase the filter frequency.
1-2: 2 Mhz 1-3: 150 Mhz
S4 Jumper settings