Specifications

85
Adjustment Procedures
When used for incoming DID calls, the 4-wire audio E&M option is usually combined
with the MF option. This is commonly known as a “Type II interconnect”.
There is a jumper JP1 on the 4-wire option board. The jumper is in the “A” position when
the paging terminal is acting as the facility side. This is usually used for incoming calls
from a telco. The jumper is in the “B” position when the paging terminal is acting as the
telco side.
There are no adjustments or additional jumpers on the board.
Audio Daughter Board (4-wire audio E&M) Rev B
JP1, JP3, JP5 on the Audio Daughter Board must be set in order to provide proper
supervision voltages to the “Trunk A” E&M pair.
JP2, JP4, JP6 on the Audio Daughter Board must be set in order to provide proper
supervision voltages to the “Trunk B” E&M pair.
For this revision, E-Lead output is the dry contact of an N.O. or N.C. relay closure, as
defined by jumpers JP5/JP6:
N.O.
Supervision voltage is only applied during the Off-Hook state, requiring IDLE (On-
Hook) bias to be applied at the telephone company's CO Interface.
N.C.
Supervision is dropped during the Off-Hook state.
The E-lead supervision voltage is selected via JP3 / JP4. These jumpers select either
(current-limited) -48 VDC, or 0 VDC to be applied to the E-lead drive relay “common”
terminal, and then to the E-lead output (through JP5 / JP6).
The M-lead must be electrically forced to the Off-Hook state at the telco CO Interface,
causing current flow through the optoisolator sensor, in order to cause an Off-Hook status
detection. During the IDLE or On-Hook state, the telco CO Interface must become “N.O.”
or biased to MATCH the JP1 / JP2 voltage selected.
Refer to Table 5 for information on jumper positions and signals for the Audio Daughter
Board (Rev B).