Questions about RS422 driver
I think that you should post separate questions.

I will answer the first one - when termination is not necessary?

If the signal is very slow (1 pulse per second definitely is), then you do not need termination. 

See for example this post from TI:


  One situation in which you don’t need termination networks is when the two-way loop time of the network is much greater than a single bit time (~&lt;0.1×two-way loop delay). In such scenarios, the reflections will lose energy each time they reach an end of the network.