In a factory setting, it is common to sound a siren before the conveyer starts moving
Write a program:
-Use TON timer only
- Push a START button to turn on a “siren” (use a small fan) for 5 seconds
- The conveyer (use BIG FAN) starts moving two second after the siren goes off
- The conveyer should keep moving until a STOP switch is pressed
- Add an EMO button to turn the system off in case of an emergency
- Push a START button to turn on a “siren” (use a small fan) for 5 seconds
- The conveyer (use BIG FAN) starts moving two second after the siren goes off
- The conveyer should keep moving until a STOP switch is pressed
- Add an EMO button to turn the system off in case of an emergency
The cooling fan should turn off a couple of minutes later after the motor has been turned off.
Write a program:
- Use TOF timer only
- Push a START button to turn on the motor and its cooling fan at the same time
-The motor and the fan should keep running once the START button has been released (latch)
-Push a STOP button to turn the motor off but the cooling fan turns off 5 seconds after the motor has been turned off
- Add an EMO button to turn the system off in case of an emergency
- Push a START button to turn on the motor and its cooling fan at the same time
-The motor and the fan should keep running once the START button has been released (latch)
-Push a STOP button to turn the motor off but the cooling fan turns off 5 seconds after the motor has been turned off
- Add an EMO button to turn the system off in case of an emergency
Oil is consumed randomly. The tank needs to be refiled and drained by turning on a pump. Two hydrostatic switches are used to detect a high and low level.
Write a program:
Write a program:
Push the START button to activate the system
- Shut off the pump (Sol A) when the full level is detected
then turn on the mixer for 10 seconds
then turn on the mixer for 10 seconds
- Turn off the mixer after 10 seconds then turn on the pump
(Sol B) to drain the tank
(Sol B) to drain the tank
- Turn off pump (Sol B) and turn on pump (Sol A) when the empty level is detected
to start refilling the tank
to start refilling the tank
- Pump A and pump B should not be ON at the same time
- Push the emergency STOP button to shut off the system
Metal shaping tools such as shears and breaks require two hand switch activation to guarantee that the operator is not trying to hold a workpiece in the cutting area. In other words, we require both hands be involved in the switch area, thereby reducing the number of insurance claims for mutilation. Regardless of the wisdom of this protocol, some operators insist on trying to defeat this safety feature by locking one switch always active, enabling themselves to operate the tool with one hand. To guard against this defeat, we require both hand switches change in unison, within a small time window, say 0.5seconds. If a mismatch exceeds 0.5 seconds, we lock out activation of the machine until both switches have been release.
Write a program:
- Push two pushbutton switches simultaneously to turn on the machine (a BIG FAN)
- The machine should stop when both hands are off the switches
- The machine locks up (a small fan turns on) and the machine won’t start if the two pushbutton switches are not activated simultaneously, say the gap is larger than 0.5sec
- The machine will be unlocked (the small fan turns off) when both pushbutton switches are released
