Question: I recieved samples of AD7175-2 and AD5684R with an instruction:

> 
> If these samples are to be subjected to solder reflow or high temperature process, they must be baked for 24 hours at 125°C prior board mount. Failure to comply may result in crack and/or delamination of critical surfaces within the package.
> 
> 
> 

Is it done in a reflow oven? Otherwise how?

I am confused because Elektor qs-5188C reflow oven in our lab seems to lack an option, that would let it run for such a long time.

Answer: 
It may just be the anode and cathode polarity indicators for an optically isolated drive signals. Here is an example product with similar terminology from Rhinomc RMCS-225X:

<http://www.active-robots.com/dc-servo-motor-10rpm-uart-12c-ppm-drive>

[![rhinomc](https://i.stack.imgur.com/guKBs.jpg)](https://i.stack.imgur.com/guKBs.jpg)

If you open the datasheet you will see the internal diodes. They leave all of them independently floating in order to allow the user to drive them as needed. (Common anode, common cathode, differential).
The presence of signals whose names differ only by "+" and "-" strongly suggests that differential signalling is being used — perhaps something like RS-422.

There is no real way to verify this without opening up the unit and trying to identify the chip(s) that these signals drive.

If it turns out that this is the case, you'll need a TTL-to-RS422 driver chip, which is readily available.