Due to different hardware versions, the TTL outputs which set the alignemnt/tandem mode of the TFPI during normal operation have to be inverted. To check this, TFPDAS5 offers a feature to check for the inversion.
Important: Before starting the check, TFPDAS must be in idle mode! For this, press Escape which stops any acquisition. Subsequently, select from the menu bar => TFP => DigitalOut => check for TTL inversion:
![](https://thatec-innovation.com/wp-content/uploads/2021/10/TFPDAS_TTL-inversion_Menu-bar-1024x583.png)