User manual

Analog Voice ModulesPassport 4400 Hardware Installation Manual
8-14
Strapping
Strapping involves matching the voice/fax channel with the attached telephone
interface. Specifically, the voice/fax channel may be strapped, depending on the
application,foroneofthreecommontypesofsignalingconventions:FXS(Foreign
Exchange Station), FXO (Foreign Exchange Office), or E&M (Ear and Mouth).
AVMsinstalled in units are usually prestrapped to the interface type specified in
the order. Restrap only if you add a new AVM, if your interface requirements
change, or if your interface requirements are different from the wayyou ordered.
them.Youmayalsoneedto temporarily restrap avoice/faxmoduleifyou perform
a level setting procedure. To verify the settings of your voice/fax channel(s)
without physically inspecting them, refer to 800-1952-20, Passport 4400
Operator’s Manual.
• In a dual-channel AVM, each channel may be strapped for a different
signaling convention.
• Place a strap over E41 (or E38 for Channel 2) if the cable to the PBX is too
long.
• Placea strapoverE21(orE18for Channel2)toconnectthebatteryground
to the SG lead.
• To select E&M, FXO, or FXS for each channel, consult the strap options
listed in Figure 8-16 below.
Figure 8-16. Location of AVM Straps
Back
Channel 2
Channel 1
E38 E39
E18
E19
E21
E20
E41 E40
E&M
FXO/FXS
E&M I
E&M II
E&M V
FXO
FXS
E&M strap options
FXO/FXS strap options
E&M
FXO/FXS
Note: Channels 1 and 2 have the same strap options, but
the straps for Channel 2 are arranged in the opppsite
direction (mirrored left/right in the diagram above).