Week 10 Update - Current Transducer and EasyIO

Hello

Last week, I ran into a roadblock where my Multi-Meter and the BASpi web interface where not displaying the same value and I did not know why. So what I'm thinking of doing this week is replace the 40 Watt Bulb with a 50 Watt Bulb like I used a couple weeks ago and seeing if my Multi-Meter and BASpi will display the same value. If so, I will do but with a 100 Watt Bulb. 

For the 50 Watt Bulb, here are the calculations as a reminder:
50 Watts (Wattage Rating for the Bulb)/120 Volts = 0.416 Amps. 
170 millivolts X 0.001 = 0.17 Volts X 2 = 0.34 Amps


Even though I used a 50 Watt bulb and did my setup like last time, I ran into some funny issues. 1: My Multi-Meter wasn't reading Voltage. I just wanted to bench test my setup and make sure my readings are the same before I put them into Sedona. 2: My professor wanted to know just what current was coming from the bulb. Unfortunately, none of the Multi-Meters I have used thus far measure AC Current, only DC current. Anyway I got an AC Ammeter and measured 0.35 Amps which is similar to the calculated value. Below I have included a picture of the AC Ammeter below:

After that, I went and measured the Voltage coming from the Current Transducer using a more stable connection and got a reading of 173 millivolts which lines up with my calculations. This is great. Remember always bench test, it will save you a lot of frustration later.

Next, my professor showed me that inside a junction box connected to the Main Power for one of the benches there was a Current Transducer (the same one in fact) and that he wanted me to measure total power consumption just like I did with the Electricity Meter way back when. I found some wires stripped them and fed them from the Current Transducer to U7 (Universal Input 7) on the EasyIO. I also hooked up power and here is my setup.

After I powered up the EasyIO and connected it to the Internet via an Ethernet cable. Now I used an IP Scanner to scan the network since the default IP Address of the EasyIO is 192.168.10.11, luckily someone who used the computer earlier this week must have changed the IP Address to 192.169.50.29 so I was able to log into CPT and access the EasyIO version of Sedona without an issue.Here is a screenshot showing CPT for login, as well as, the program I made in Sedona:

Now, I will explain each component of my program for you.
CTVolts: This is the Voltage coming from the Current Transducer into Universal Input 7. Just like with the BASpi, it's not the same as what what I calculated.
WriteFl: This is simply just a value created by me for calculations, in this case the value is 2.00.
Mul2: This just Multiplies 2 numbers and spits out an output. In this case it multiples CTVolts and WriteFloat (0.07 X 2) to get 0.14. We're almost there.
WriteFl1: Another value I made, this time the value is 0.03.
Add2: This Adds 2 numbers and gives and output. This one adds the output from Mul2 and the 2nd WriteFloat (0.14 + 0.003) to get 0.17. This is even better as this is the value I saw on my Multi-Meter and in my calculations.
WriteFl2: Yet another value I created, this has a value of 2.00.
Mul21: Another Multiplier which multiples the output from the Add2 and WriteFl2. (0.17 X 2) to get 0.33. Again this is great as this is the Current I calculated and saw on the Clamp-On Meter and the Analog Ammeter.
Current: This is just UO1 (Universal Output 1) and this just displays the output of Mul21. 

Remember that for CTVolts, the input type has to be voltage0-10volts otherwise you won't see a number. On the other hand, for Current, the output type has to be Current0-20mA otherwise you will not see a value. In my physical setup, I had to make sure the EasyIO jumper wires matched what type of value I was measuring. Here are some pictures showing off the jumper guide inside the EasyIO cover and the correspoding jumper wire placment on UI7 and UO1.

Next week, I want to get BACnet working in EasyIO and transfer what I did today into Azure. But, I also want to play with the code so that the current is accurate to what I would have read on the Electricity Meter I used a while back. Speaking of Electricity Meter, I want to the modify the code so it displays the same wattage I saw on the Meter which will then be multiplied by 12 so it gives me the total power consumed by the benches in C527.

- Valentin