Cisco EM-HDA-3FXS/4FXO High-Density Analog 3-Port FXS 4-Port FXO Voice Fax Expansion Module

The Cisco EM-HDA-3FXS/4FXO is a 7-port analog voice and fax expansion module that adds three FXS ports and four FXO ports to a Cisco High-Density Extension Module. The EM-HDA-6FXO adds six FXO ports, the EM3-HDA-8FXS/DID adds eight FXS or DID ports and the EM-4BRI-NT/TE adds four BRI ports, while this module mixes three on-premises FXS ports with four off-premises FXO ports. The FXS side serves existing phones, faxes, PBXs and key systems, and the FXO side connects to the central office. It installs on the EVM-HD-8FXS/DID baseboard, which takes up to two expansion modules in any combination and scales to 24 voice and fax sessions. Loop-start and ground-start signaling are both supported, and address signaling can be in-band DTMF or out-of-band pulse at 10 pps. FXS loop resistance can reach 600 ohms, and ringing is 40 Vrms at 5 REN with 25 Hz and 50 Hz frequencies available. Call disconnect is detected from a progress tone, battery polarity reversal or a power interrupt longer than 600 ms. Signal processing comes from PVDM2 modules that are purchased separately for the baseboard.