Creating devices is difficult. How would a PLC read variable Ohmic, or variable mA input values.
I am guessing with the Variables If that is true how would you test this?
I do not understand you about your comment 'creating devices', please explain.
About numeric values, you must use int, long, float or double variables, declare it in the variables section, then use it in the program.
Also you can use the analog I/O signal of the drivers, if you are using a driver that have analog signals take count that in EasyPLC all analogic values are float type.
I recommend you to read the EasyPLC User Manual (in the chapters 2.3.1 & 2.4.1.5 are explained how to use variables).
Hope this help you.
Hello
My problem is I do not understand "C" language.
I am trying to figure how to use the Variables to read an RTD. The RTD I wish to read is is a Platinum PT100, the resistive value at zero degree centigrade is 100ohms and the resistive value at one hundred degrees centigrade is 138.51ohms.
I not located the section in "variables" that allows me to specify my range or set point.
I understand that using an RTD directly to a PLC is not common, and will more than likely require a RTD transmitter converting the Ohmic value to 4-20mA or 0-5vdc or 0-10vdc
Once I select Float on the Variable where do I enter the needed information?
How do I instruct it to differentiate between Ohm's, Amp, and volts?
Hi Richard,
Where is this RTD connected to? On a PLC this would be connected to an analog input module.
Also you could have it plugged in to an arduino, and you could use the arduino driver to read that signal.
Without the proper hardware and or use of driver you won't be able to read the input.
My next question is do you actually have an RTD or you are trying to simulate?
Fernando B.
Hello Fernando
I do not have an RTD with me, I am scheduled to return work aboard a ship in three weeks, I hope to understand some simple programing to experiment with RTD's, and pressure transmitters.
I do have an arduino UNO but again the C programing troubles me. I hope to be able to use the Arduino to connect the virtual PLC to real components.
I hope to be able to simulate components that reflect real components.
Aboard the ship I work on we have an Alarm and Monitor system, the section I am concentrating on is the Temperature monitoring presently The RTD signal conditioning card works on 0Vdc Common, +24Vdc, +15Vdc, and -15Vdc.
The output to Analog Gauges is 0Vdc to +10Vdc. The RTD is 0Vdc at 92.9 Ohms at zero degree Fahrenheit, and at 250 degrees fahrenheit the ohmic value is 147.38 and +10vdc.
I hope I haven't jumbled all this up but I probably have
Richard
As fredz0003 says, the input devices are connected to an analog PLC input card, the fact about their physical implementation for be able to read any kind of physic value (volts, amperes, Ohm, temperature, pressure, etc...) is totally independent from the software (belong to the hardware and driver scope), this means that at software level we are working with discrete values, the only fact important in software is to assign it the correct data type (integer, decimal, ...)
Then, in EasyPLC, once you have declared the variables, you can use it in the script program (C# language) or in Ladder or any of the available.
I recommend you to see the examples because are numeric variables processed in the programs and can serve to you as example.
I use the variable to read the analog input, AI.0.0 selecting Float
How do specify the range of Float to be read, start at zero thru five?
How would or where would this be displayed?