libnexstar
C API to control NexStar compatible telescopes
...Communication to the hand control is 9600 bits/sec, no parity and one
stop bit via the RS-232 port on the base of the hand control.
Communication can be established over TCP/IP if nexbridge is running
on the computer connected to the telescope.
To control network based telescopes nexbridge must be used on the remote site.
https://sourceforge.net/projects/nexbridge/