Analog Input PLC

[Steve Cheung]

Hi friends,

Who know where I could find samples of analog input programs?

I have a project to measure the flasher rate of flashing relay by analog input plc.

Somebody could help?

Thanks

 

[tomneth]

Not sure what you're trying to do but if you wanted to know how many times a relay comes on or off I think you could do that with a discrete input. Use a timer and counter in your PLC to see how many times the relay changes state per time unit. Is this what you're trying to accomplish?

 

[Tom Jenkins]

Think about it Steve - how could anyone satisfactorily answer a question so broad? I could give you analog programs that would be of no help - as a matter of fact I did one the other day on this site - search for MicroLogix 1000.

What PLC are you using? What kind of analog unit? Do you really need analog or a pulse frequency? What should your program do?

Is this a school project?

You have to do the hard work of clearly defining your situation and the logic and the parameters. Then we can help you.

 

[Steve Cheung]

Thanks guys,

I need to modify the data of the existing machine that PC base.
The Flasher relay signal is going to the analog input of the PC.

The relay must test by 3 kind voltage (11VDC, 12.8VDC, 6V) then,
the display will show:

Some sample of data that show at the CRT Machine as below:

TURN ON A DELAY A: 0.45 SECOND (DURATION WHEN PULSE ON)
TURN ON A DELAY B: 0.75 SECOND (DURATION WHEN PULSE OFF)
TURN ON RATE: 46.1%
TURN ON TIME: 84 SECOND


Turn On Time is: After 5 cycles of flash, measure three flashing cycle time (second)
Turn On Rate is: After 5 cycles of flash, measure three flashing cycle time(second) and current ON time (second).

I would like to ask:

Can PLC measure the Duration of pulse 0.001 second between on and off using analog Analog Input ? I would like to use PLC Mitsubishi A1SHCPU.