Panagiwtis Posted July 28, 2014 Report Share Posted July 28, 2014 Hello unitronics community, I am relatively new to unitronics plcs so forgive me if the problem I am facing is ridiculously easy to solve. I have a project that includes an energy meter, that is connected with one digital output in the V200-18-E2B expansion card (connected to a V570). I would like to display in a screen of my V570 the energy consumption in kwh via a numeric variable. I know that I must use pulse in order to do that, but at this moment I can't manage to find a way to achieve this. Any help? Every suggestion is more than welcome... Quote Link to comment Share on other sites More sharing options...
EduMarg Posted July 28, 2014 Report Share Posted July 28, 2014 Hello Panagiwtis. First you need to to the linearization of the analog variable to numeric values in the units you whant to mesure (KW) To messure the energy in one hour you can use a timer that reset itself every hour. With the output of the timer you store the value of KW to a new memory register. In the HMI configurator of VisiLogic you have the option to add: a bargraph, meter, led bar. This graph you can link to the linearize value. To view the value you can use a numeric box and also link it to the linearize value. If you need more help you can write to support@unitronics.com Quote Link to comment Share on other sites More sharing options...
Panagiwtis Posted July 28, 2014 Author Report Share Posted July 28, 2014 Hello EduMarg and many thanks for the reply. The problem is that according to the electrical scheme, the energy meter appears to be connected to a digital input of the plc, not an analog one. So , if I understand correctly your post, there isn't any linearization to be done... Quote Link to comment Share on other sites More sharing options...
sgull Posted July 28, 2014 Report Share Posted July 28, 2014 Hello unitronics community, I am relatively new to unitronics plcs so forgive me if the problem I am facing is ridiculously easy to solve. I have a project that includes an energy meter, that is connected with one digital output in the V200-18-E2B expansion card (connected to a V570). I would like to display in a screen of my V570 the energy consumption in kwh via a numeric variable. I know that I must use pulse in order to do that, but at this moment I can't manage to find a way to achieve this. Any help? Every suggestion is more than welcome... Hi Panagiwtis Firstly you should configure your meter to what ever pulse rate works best. I have used something like a rate of 2-3 pulses per second on a standard input. The meter will have settings such a 1 pulse per kwh or 1 pulse per 100 watt hour etc. Choose a setting that when at full output you have 2-5 pulses per second. See attached Regards Denis Quote Link to comment Share on other sites More sharing options...
Panagiwtis Posted July 28, 2014 Author Report Share Posted July 28, 2014 Sgull I can't thank you enough for your response!! That seems to be the way to do it, I have to examine it more thoroughly but I am very confιdent that this is the solution to the problem I am facing. If this is any further help, the energy meter is from Schneider Electric and is model A9MEM3110. Quote Link to comment Share on other sites More sharing options...
Panagiwtis Posted July 28, 2014 Author Report Share Posted July 28, 2014 Sgull, in the second screenshot in the first comment line you write: "Use MI3 value for a totaliser", but I can't see any MI3 in the ladder... I suppose that you mean ML0 instead of MI3, is this right? I imagine that totaliser is the one I want to display in the numeric variable in the HMI, isn't that right? Quote Link to comment Share on other sites More sharing options...
sgull Posted July 28, 2014 Report Share Posted July 28, 2014 Sgull, in the second screenshot in the first comment line you write: "Use MI3 value for a totaliser". I suppose that you mean ML0 instead of MI3, is this right? Yes ML0. I had originally used MI3 but then thought that this number can get very big as a totaliser so I changed to an ML. Apologies for the error. There is also an example in VISILOGIC for flow and totalising which use a 2.5ms interrupt to measure the time between the pulses to get a rate. This works very well if your pulses are uniform in pulse length. I have tried this on meters with some success. The way mentioned in the other post gets more accurate with an increasing number of pulses and a longer sampling time. If you sample for one hour you will be 100% accurate but you will have only one reading per hour. Regards Denis Quote Link to comment Share on other sites More sharing options...
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