Filter
Top Products
Voice Configuration Reference Information C-17
proximity. Check with the PBX manufacturer regarding connecting the PBX AC
ground to telco/PTT ground.
NOTE: Connecting AC grounds and telco/PTT grounds of telephone equipment may
violate rules of certain regulatory agencies. Check with your local telephone company
and/or agency regarding regulations that deal with grounding.
Interface Conversions
Different telephony interfaces can be configured at the local and remote SmartSwitch
1800s. Through Voice System Configuration (page 13-3), each device is informed of
the interface type used at the remote end. Signaling conversion is done in the multi-
plexing software without the aid of any external equipment. The following combina-
tions are supported:
E&M to E&M
E&M to OPX Loop Start
E&M to SLT Loop Start
OPX Loop Start to OPX Loop Start
OPX Loop Start to SLT Loop Start
Application Examples
In the following examples the term "attached device" refers to tie line
equipment such as the SmartSwitch 1800.
E&M Type I
Idle Condition: The "E" lead is biased by the PBX at -48 Vdc. The "M" lead is biased
at 0 Vdc by the attached device (SmartSwitch 1800).
PBX-Initiated Call: The PBX supplies -48 Vdc to the "M" lead, signaling to the
attached device that it wants a connection. The attached device grounds the "E" lead,
signaling the response.
Attached Device-Initiated Call: The attached device grounds the "E" lead, signaling
to the PBX that it wants a connection. The PBX supplies -48 Vdc to the "M" lead, sig-
naling the response.
PBX-Initiated Disconnect: The PBX initiates disconnection by opening the "M"
lead. The "M" lead is pulled to 0 Vdc, as biased by the attached device. In response,
the attached device opens the "E" lead, which is pulled to -48 Vdc, as biased by the
PBX.
Attached Device Initiated Disconnect: The attached device initiates the disconnect
by opening the "E" lead. The "E" lead is pulled to -48 Vdc as biased by the PBX. In
response, the PBX opens the "M" lead, which is pulled to 0 Vdc, as biased by the
attached device.