Positioning - Omron CJ1W-CT021 Operation Manual

Positioning

6-3

Positioning

Application Description
Motor 1 Forward (=0) / Reverse(=1)
Motor 1 Fast (=1) / Slow (=0)
Motor 2 ON (=1) / OFF (=0)
Motor 1 ON (=1) / OFF (=0)
Encoder (Feed) Motor1
154
Covered configuration items in this example:
• Linear Counter
• Comparison Mode, setting Comparison Data
• Digital Input Function (Function 05)
• Using IOWR-instruction to change Comparison Data
In this example a hole is drilled into an object. The drill bit is spun by a single
speed, single direction motor (motor 2) which can only be turned ON or OFF. The
feed motor has two speeds (fast/slow) and can travel in two directions (forward/
reverse). The High-speed Counter Unit controls the speed and direction of the
feed-motor and turns ON/OFF the drill-motor. Turning ON and OFF the feed-motor
is done by the PLC ladder program via a Digital Input- and Output Unit (e.g. CJ1W-
ID231/OD231). A proximity switch is also connected to the Digital Input-and Out-
put Unit and reports to the CPU via the ladder program that an object is ready to
be treated. Consequently via the ladder program the feed-motor is turned ON.
An incremental encoder is connected to the shaft of the feed-motor. The encoder
is connected to Linear Counter 1. The Unit is in Comparison Mode and four Com-
parison Values are defined to control the speed and direction of the feed-motor
and to turn ON and OFF the drill-motor. The limit switch is used to reference the
home position of the drill-motor by resetting the Counter Value to zero.
Limit switch
(Drill)
Motor2
M1 Slow/Forward
0
CV0=5000
M1 Slow/Revers M1 Fast/Reverse and M2 OFF
0 CV0=5000
After an object has been detected the feed-motor (M1) is turned ON (slow/for-
ward). When CV0 is passed M1 is switched to move fast. Reaching CV1 causes
the drill-motor (M2) to turn ON. At CV2 the feed-motor is switched to move slow.
Reaching CV3, when the hole has been completed causes the feed-motor to
reverse direction and to move back with fast speed (Counter 1 now counts down).
Other machinery (that is not visible) now automatically removes the object and the
proximity switch becomes inactive. At CV1 the drill-motor turns OFF and at CV0
CT021
RUN ERC ERH
CH1 A B Z
CH2 A B Z
20 20
CN1
MODE
1 1
B A
M1 Slow/Forward
M1 Fast/Forward M2 ON
CV1=35000 CV2=37000
M1 Fast/Reverse
CV1=35000
OD231 ID231
0 1 2 3 0 1 2 3
4 5 6 7 4 5 6 7
I0 O0 8 9 10 11 8 9 10 11
I1 O1
12 13 14 15 12 13 14 15
0 1 0 1
1 1
1 1
20 20 20 20
A B A B
Object
CV3=40000
CV3=40000
Section 6-3
Proximity switch