Autoguide Interface circuit diagram is shown here.
There are several point that the user must be aware of. In the K3CCDTools
guiding software there are five outputs (RA+, RA-, RA Stop, DEC+, and DEC-).
However, The Celestron Autoguide interface uses only four signals (RA+, RA-,
DEC+, and DEC-). For proper operation, the K3CCDTools RA Stop output is mapped
to the Celestron RA+ input. The K3CCDTools RA+ output is not used. All other
mappings are like name output to input.
use this circuit for the standard PISCO interface found on Astrosnap and Astrort
CCD plugins but the CD4094 pins must be reconnected differently as shown in the