If you can connect to the mount using the usb cable , (not sure why it is often referred to as a serial cable) , and then run the PMC-Eight Configuration Manager, and on the Advanced Screen set the communication method to UDP. That might work.
Mounts: ES PMC-8 IEXOS-100
Cameras: Canon 1200D, Canon 70-210mm, Tamron 150-600mm, 50mm prime.
Msc: 12V Powerbank
Software: ExploreStars, SharpCap, All Sky Plate Solver