Speed Control - Omron CJ1W-CT021 Operation Manual

Speed Control

6-5

Speed Control

Application Description
Control Panel
Start Conveyor Motor + Saw Blade
Stop Conveyor Motor + Saw Blade
Motor ON (=1) / OFF (=0)
Motor Fast (=0) / Slow (=1)
Motor
164
Covered configuration items in this example:
• Circular Counter
• Rate Ranges, setting Rate Range Data
In this example logs are fed into a saw blade. A conveyor that has two speeds
(fast/slow) transports the logs. Via the control panel the conveyor and the saw
blade can be started and stopped. A speed sensor detects the speed of the saw
blade. The pulses of the speed sensor are counted by Counter 1 and are propor-
tional to the speed of the saw blade.
Logs are fed into the saw blade at fast speed. When the saw blade encounters an
irregularity in the log, the speed of the saw blade slows down. Now the conveyor
is switched from fast to slow speed (slow speed indicator turns ON). Once the saw
blade clears the irregularity and returns to its normal speed, the conveyor is
switched from slow to fast speed again (slow speed indicator turns OFF).
Speed Sensor
The speed sensor is connected to Circular Counter 1. The two Rate Ranges
(Range 0 and 1) of Counter 1 are used to detect the speed of the saw blade. Turn-
ing the conveyor motor and the saw blade ON/OFF, using the control panel, is con-
trolled via the PLC ladder program and a Digital Input- and Output Unit (e.g.
CJ1W-OD231/ID231). The speed of the conveyor motor is controlled by Digital
Section 6-5
ID231 OD231 CT021
RUN ERC ERH
0 1 2 3 0 1 2 3
4 5 6 7 4 5 6 7
8 9 10 11 8 9 10 11 CH1 A B Z I0 O0
12 13 14 15 12 13 14 15 CH2 A B Z I1 O1
0 1 0 1
1 1 1 1 20 20
CN1
MODE
20 20 20 20 1 1
A B A B
B A
Slow Speed
Indicator