Lab-Volt 5100 Robot Arm – Suspected Interface Spec.

This is what we have so far. It is not a totally complete reverse engineering of the board.

DB9 Pinout – Located on the base of the machine.
1 – GND
2 – LATCH
3 – A1
4 – Motor Phase D
5 – Motor Phase B
6 – A0
7 – A2
8 – Motor Phase C
9 – Motor Phase A

 

Signals are 0-5V TTL.

The robot has 6 axis of motion, 1 auxiliary axis, 4 digital outputs, and 3 high-power outputs.
Each axis is addressed with A2, A1, A0 like so:

A2 A1 A0 Axis
————-
0 0 0 1
0 0 1 2
0 1 0 3
0 1 1 4
1 0 0 5
1 0 1 6
1 1 0 Aux
1 1 1 Digital / High-power outs (?)

The motors are unipolar with 4 phases: A, B, C and D.
To move the motors, output the following phase pattern in sequence:

Step A B C D
————
1 1 0 0 0
2 0 1 0 0
3 0 0 1 0
4 0 0 0 1

This is called “single-stepping.” Reverse the sequence to spin the motors in the opposite direction.

Use “double-stepping” for twice the resolution, if desired:

Step A B C D
————
1 1 0 0 0
2 1 1 0 0
3 0 1 0 0
4 0 1 1 0
5 0 0 1 0
6 0 0 1 1
7 0 0 0 1
8 1 0 0 1

To send a phase pattern to a motor, select the axis with A2:0, output the pattern on A,B,C,D then bring LATCH high.
The outputs are updated on the rising-edge of LATCH.