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Hi
I am trying to access the step motor with an auxiliary controller. By connecting an oscilloscope to the control signals (A,B,C and D) we saw TTL patterns which seems to carry the information about direction and step length. Thus I would like to ask you for the TTL patterns of step size 26nm and 998nm up and down?
Additionally, I would like to ask you if switching from Input to Output of the signal access module harms in any way the electronics of the controller or the STM base?
Thank you and best regards,
Florian
Florian,
The Multimode uses a Stepper motor with the motor lines, A, B, C, D, directly connected to each phase of the motor. We use the 1/2 step mode in this order:
Step
D
C
B
A
1
0
2
3
4
5
6
7
8
Note: The signal is Active Low, so where you see a 1, that is 0 volts, 0 is TTL high. Each 1/2 step is 26 nm using the original scanners (has adjustment knobs on bottom), the Vertical Engage scanner is about 120nm per step. Just reverse the step order to reverse the motor.
Peter Lombrozo
Senior Software Engineer
Nano Surfaces Business
112 Robin Hill Rd.
Santa Barbara, CA 93111
805-967-2700, X2245
Peter.Lombrozo@bruker-nano.com
Dear Peter
For our Multimode III we observed a pattern like this for a step size of 26nm:
Step 1: 0 1 1 1
Step 2: 0 0 1 1
Step 3: 1 0 1 1
Step 4: 1 0 0 1
Step 5: 1 1 0 1
Step 6: 1 1 0 0
Step 7: 1 1 1 0
Step 8:0 1 1 0
Which is different of the one you posted. Anyway, I suppose the sequence of the pattern does not matter, is that right?
Normal 0 false false false false EN-US X-NONE X-NONE
Sorry, typo in 2nd line, should be:
0 0 1 1
which I’ve fixed. Actually, we’re on the same page. My table was the TTL logical signal, but as I said in the note, since it is TTL active low, each 0 is TTL high (5V) and 1 is 0 volts. Also, my table was D,C,B,A, yours is A,B,C,D which is more readable. Step size for you really doesn’t matter here, each position is ½ step which is 26nm. We just take more steps at a time for larger step sizes.
Also, the sequence does matter, though starting point doesn’t. Without going through the phases in the right order, the motor won’t move. In fact, it won’t move even then until you get to the phase that matches the motor present state, so its best to always save the last position.
Thank you for your helpful answer.
Unfortunately, it seems that the stepper motor is not turning anymore by our software & hardware control and by the Nanoscope software either. Although, it moves by the manual switch.
We measured the signals coming from both Nanoscope control and our home-built control and it seems that the TTL signal of B has just 2V. It puzzles me since it happened to another base of ours too.
We use the Signal Access Module to inject the TTL signals.