Zero point 4-20mA

Hello,

I have some troubles to set the analog 4-20mA signal to zero. I have connected a 0-3 meters pressure sensor to measure the level in a tank. If the connected sensor reads 3,8mA (or 4,1mA or something like that) i want to zero point de level in the tank to 0 centimeters.

I only want to set this once to zero when installing the sensor.

The example on this forum works fine for me, the only problem is that when the power is down of the LOGO the zero point setting is also reset. (mathematic instruction)

Is it posibble to use de F-buttons on the TDE to set the reading from the sensor to 0 centimeter.

I hope someone can help me.

Best regards Sander