The basic functionality of RVP24 and ROP25 is the same, but ROP25 has builtin fibre optic modems (2 items) and therefore cabling on the synchronous side is replaced with fibre optic cables which eliminate problems caused by induced noise into long cables.

Recommendation is to use RVP24 when cabling is not exceeding 3-5 mtr. Beyond this use ROP25 or RVP-NET

Because 2 modems are involved this solution is delivered as 2 separate items and 2 power supplies.