Hi, I need to program on a mitsubishi aplha2 series using function blocks. Any help will be greatly appreciated. here is the task
The PLC is an add on to an old blister packing machine which is now upgraded with a camera to check for good/bad tablets. when the camera system gets a trigger pulse from machine it takes a snap shot of the blister cavities and decides whether it is a good or bad (+ve or 0 volt) output to the PLC. The timing of the output of the camera is immediately after receiving the trigger pulse. if it is good blister pack then the output is +24v pulse for few milliseconds. (time the +24v stays on is equivalent to the duration you can blink your eye as fast as possible)after that it goes to 0Volt until camera system gets next trigger pulse. then if the output is for a bad blister pack, there will be no voltage for a few milliseconds then the output turn on until it gets next trigger pulse.
Now I need to turn on and turn off a solinoid valve to reject or accept the blister according to the output of the camera system. The solinoid has to be turned on more than the duration of the blink eye time and the solinoid has to wait until the blister reaches the reject position of the machine or accept position of the machine (there is an encoder on the machine for the positioning and I have few spare outputs that can be programmed from the HMI on the machine PLC according to the reject/accept timimg, such as turn the purticular spare output at machine position from, say 120 degrees to 245 degrees etc).
On the mitsubishi PLC AL2-14MR-A,I gave these to the input
1. Trigger pulse
2. Camera output
3. Reject Position timing
4. Accept Position timing
I gave the Trigger to a ONESHOT block and gave the pulse duration to 70ms, then the output of the ONESHOT and camera output to an AND, if both are on at the same time then it is good pack and the output of the AND will turn on SET/RESET block, its output and the accept position pulse are given to an AND, so the AND will give output when accept pulse turn on.
For the reject blister function, I gave the Trigger pulse to a ONESHOT, and its output and the output of the camera to a XOR, if both input to XOR are on then no output, if only one input is on then the XOR gives an output which activates a SET/RESET then to an AND with Reject position Pulse as explained above.
This idea is working at lower speed of the machine such as around 40 blisters per minute,(around 1.5 seconds between two trigger pulses) but I think the use of ONESHOT to determine the +24v or 0v can create problems at higher speed (around 0.5 seconds between two trigger pulses)
PLC- AL2-14MR-A
Any one can help me to get better logic than the one used PLease...
please find attachment for the function block diagram.
Kind Regards,
Blessen
The PLC is an add on to an old blister packing machine which is now upgraded with a camera to check for good/bad tablets. when the camera system gets a trigger pulse from machine it takes a snap shot of the blister cavities and decides whether it is a good or bad (+ve or 0 volt) output to the PLC. The timing of the output of the camera is immediately after receiving the trigger pulse. if it is good blister pack then the output is +24v pulse for few milliseconds. (time the +24v stays on is equivalent to the duration you can blink your eye as fast as possible)after that it goes to 0Volt until camera system gets next trigger pulse. then if the output is for a bad blister pack, there will be no voltage for a few milliseconds then the output turn on until it gets next trigger pulse.
Now I need to turn on and turn off a solinoid valve to reject or accept the blister according to the output of the camera system. The solinoid has to be turned on more than the duration of the blink eye time and the solinoid has to wait until the blister reaches the reject position of the machine or accept position of the machine (there is an encoder on the machine for the positioning and I have few spare outputs that can be programmed from the HMI on the machine PLC according to the reject/accept timimg, such as turn the purticular spare output at machine position from, say 120 degrees to 245 degrees etc).
On the mitsubishi PLC AL2-14MR-A,I gave these to the input
1. Trigger pulse
2. Camera output
3. Reject Position timing
4. Accept Position timing
I gave the Trigger to a ONESHOT block and gave the pulse duration to 70ms, then the output of the ONESHOT and camera output to an AND, if both are on at the same time then it is good pack and the output of the AND will turn on SET/RESET block, its output and the accept position pulse are given to an AND, so the AND will give output when accept pulse turn on.
For the reject blister function, I gave the Trigger pulse to a ONESHOT, and its output and the output of the camera to a XOR, if both input to XOR are on then no output, if only one input is on then the XOR gives an output which activates a SET/RESET then to an AND with Reject position Pulse as explained above.
This idea is working at lower speed of the machine such as around 40 blisters per minute,(around 1.5 seconds between two trigger pulses) but I think the use of ONESHOT to determine the +24v or 0v can create problems at higher speed (around 0.5 seconds between two trigger pulses)
PLC- AL2-14MR-A
Any one can help me to get better logic than the one used PLease...
please find attachment for the function block diagram.
Kind Regards,
Blessen
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