How is the Spectra IV dome controlled if there is only a coaxial cable and camera power pulled to the dome location?
Spectra IV Series
The front end system support coaxitron control, which does not require data wires.
The majority of Pelco Digital Video Recorders and Matrix Switching systems have Coaxitron (up the coax) control included. If not a CM9760-CXTA
Coaxitron Translator can be added to translate RS422 P or D signals to Coaxitron. When using Coaxitron RS422 data wires are not necessary.