This document outlines the steps to define the motion sequence and control logic for a pneumatic drilling machine with two actuators. It explains how to 1) define the motions of each actuator, 2) divide the sequence into groups, 3) determine the status of limit switches for each motion, 4) identify the number of connecting lines and reversing valves required to control the two actuators. It then provides an example machine and illustrates how to apply the five steps to model its control logic.

2.  Define motions of all actuators
 Divide sequence into groups
 Determine limit switch status
 Identify number of connecting line
( = number of groups)
 Identify number of reversing valve
( = number of groups – 1)

3.  Example
◦ A pneumatic actuated
drilling machine,
contained of two DAC.
When the workpiece is
located at it position,
cylinder A will clamp the
workpiece. Then, the
drilling process is started,
where the spindle is
controlled by cylinder B.
After finish drilling,
cylinder B will retract to
the initial position, before
the clamping cylinder
retract.

4. 1. Define motion
A+ B+ B- A-
2. Groups
A+ B+ B- A-
K1 K2

5. 3. Limit switch status
A+ B+ B- A-
Start
A1
B1
B0
A0
Above
Below

6. 4. Number of connecting line
= number of groups
= 2
5. Number of reversing valve
= number of groups – 1
= 1

7.  Mechanical sensor, initial position
 Activated position

8. 2
connecting
lines
1
reversing
valve

9. A+ 
Start + A0

10. B+  A1

11. B-  B1

12. A-  B0

14. 4 2
5
1
3
14 12
0 V

15. 4 2
5
1
3
14 12
4 2
5
1
3
14 12
0 V6
0 V5