4-20mA to 0-20mA in tiaportal

Automation PLC
1

Hello,

How can I convert 4-20mA to 0-20mA in tiaportal?

2

:white_check_mark: How to Configure Siemens Analog Input for 0–20 mA (instead of 4–20 mA)

:one: Open TIA Portal → Device Configuration

  • Go to Devices & Networks

  • Select your PLC (S7-1200 / S7-1500)

  • Click the analog module (AI card)

:two: Select the Analog Input Channel

  • Click on the module

  • In the right panel, select the channel (AI0 / AI1 / …)

:three: Change Measuring Type (Current Range)

Under “Properties” → “Channel” → “Measuring Type”
You will see options like:

Common Siemens AI Options:

  • 4…20 mA

  • 0…20 mA

  • ±20 mA

  • Voltage ranges (0–10 V, ±10 V, etc.)

:backhand_index_pointing_right: Select:

:check_mark: 0…20 mA (unipolar current input)

This tells the card to treat 0 mA as minimum instead of 4 mA.

:four: Apply & Download Changes

After setting 0–20 mA, press:

  • Compile

  • Download to device

  • Put CPU in RUN

Now your analog input will interpret 0–20 mA correctly.

:test_tube: Important Note About Raw Values

After setting 0–20 mA, the Siemens raw values change:

0–20 mA → 0 to 27648 counts

So you get:

Current Raw Value
0 mA 0
10 mA ~13824
20 mA 27648

No scaling offset is needed.