Trendnet TVP-224HR User Manual

TVP-224HR User’s Guide 

108 

 

The following diagram illustrates two different types of connections. The SITE A  
FXS Connection shows the normal connection between a gateway and telephone 
set (POTS) or FAX machine. The other type of FXS connection is shown on SITE 
B, on the right hand side. The Connection between the gateway and PBX has a 
special CO trunk interface card. The telephone sets connected to PBX can be 
either POTS or digital telephone depending upon the PBX capability. 

 

Normal FXS 
Connection 

FXS Connection  
w/ CO Trunk 
Interface Card 

TVP-224HR 

TVP-221H 

 

 

Application 2 has three possible connections. One Site A, the FXS connection to 
analog devices is normal and is identical to connections mentioned in Application 
1.  On Site B, the connection between PSTN and PBX is also a normal 
connection. The last connection is between PBX and the gateway which uses the 
internal analogue lines of the PBX. In this case, the FXO port has to be used. 

 
Note: If a digital PBX is used, an analog terminal adapter is needed to provide an 

analog interface to the FXO port. Please consult with your PBX supplier. 

 
In this application, the caller on Site A, can make a call using a device connected 
to a FXS port on the Site A gateway.  The call will be routed to the Site B 
Gateway,  through a FXO port and passed on to the PBX system. The PBX 
system will then forward the call to the dedicated terminal / extension. 

TVP-224HR 

TVP-221H 

Normal FXS 
Connection 

Normal 
FXO Connection