4-20mA Current Loop Transmitter: Help

Products
1

Hello,
I am using the 1-Channel Isolated 4-20mA Current Loop Transmitter With Power Supply (PR33-49) I want to control pressure control valve. I measure 36mA output Signal. I dont thinkt the transmitter is malfunctioning I ordered 3 and everytime its the same problem.
I control the loop transmitter with a raspberry Pi.
Any help or advice is greatly appreciated, thanks!

2

36mA is theoretically impossible give thant its range is limited to 22mA.

  1. can you measure voltage across the terminals
  2. can you share a picture of your setup
3

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Voltage is 12V
The Red abd the Blue cable are going directly to control the pressure valve

4
  1. are you powering the board using 3.3V or 5V. you should be using 5V.
  2. RPI does not have any i2c pull ups , so you should be installing on board pull up jumpers
  3. remove any connection from the board and measure current across the two terminal as well.

Thanks

5
  1. Yes I am Powering the board with 5V
  2. What do you mean with install Pull up jumpers?
  3. the output ist 36mA
6

you need this rpi shield
https://store.ncd.io/product/i2c-shield-for-raspberry-pi-3-pi2-with-outward-facing-i2c-port-terminates-over-hdmi-port/

7

Hmm Okay… but this device does the same like i did with the jumper wires? it is just connecting the RPI with the current loop transmitter…

Im also not sure what exactly the I2C Adress Jumper does und the Pull-Up Jumpers?

8

RPI i2c is 3.3v and the 4-20mA board runs at 5V.

9

Yes, thank you that seems to be the problem… Does the rpi shield you recommended solve the problem?