Add method to check for error in robotHW component

[bochen87]

I'm proposing to add a method to check for errors in the hardware components, especially when having multiple HW components, it becomes quite cumbersome otherwise.

[bmagyar]

Could you please demonstrate an example use-case, perhaps through some unit tests?

[bochen87]

@bmagyar added a very basic test to it. I guess could also be very useful in conjunction with #294 to then automatically attempt to recover / stop

[mathias-luedtke]

Who would call this hasError function and why?

[bochen87]

At the moment I use this in the main loop and then attempt to recover / stop if it returns true.

[mathias-luedtke]

attempt to recover / stop if it returns true.

This is the interesting part.. I believe there are no interfaces for this yet.
In ros_canopen I poll and command the hardware directly.

[bochen87]

No, there is no interface for that yet - that's why I would like to see #294 being extended to combined_robot_hw and also merged.
Maybe add the extension of stop / recover to combined_robot_hw and the error checking interface in one PR?

[bochen87]

@bmagyar @ipa-mdl any thoughts?

[jlack1987]

Would just like to throw this out there in case nobody has considered it, but it appears the API is converging on an orocos component like design

[bochen87]

@bmagyar @ipa-mdl any thoughts?

Bump