SP140 is designed for analog card A1200P. It's to split RJ45 jack to RJ11 jack that is used to connect the telephone line.
FXS-200 is a dual-channel module with an FXO channel and one FXS channel with failover capability. When the PBX fails, the line of the Public Switched Telephone Network (PSTN) connected to FXO will automatically switch to the analog phone connected to FXS.
FXO100 cards from the A400 / A800 / A1200 series