Ericsson BDV BS 101 01 - Page 21

22(46)
Date
Rev
Documentnumber
Prepared
Doc respons/Approved Checked
Reference
1998-05-29 L
1531-BDV BS 101 01 Uen
INSTALLATION INSTRUCTION
Subject responsible
6.10.3 E&M-signalling
Signalling on E & M wires is done either using one or two E&M pairs depending on what is required. Using just E1
and M1 is a very common practice. One case to mention is the American E&M signalling where the M1 wire toggles
between -48VDC and 0V.
Double E&M signalling requires the E1/M1 wires for the signalling of information and the E2/M2 wires indicate
blocking of the connection. The E1/M1-wires are used for signalling and E2/M2-wires are used for blocking. The
figure shows 0V connection to the M-wires in both ends.
Figure showing four wire speech and standard (double) E&M signalling.
S7
M1 E1
M0
E0
-48V
0V
-48V
0V
E1 M1
E0 M0
6A18
6A20
6C18
6C20
0V
0V
M1
S8**
-48V
M3**
**application specific
0V
DSLAC
4A18
4A20
4C18
4C20
PBX
R
LA
LB
LC
LD
autom. 2/4wire
0V
PBX or channel equipment
Detector
Detector
M2 E2
M20
E20
0V
-48V
0V
-48V
0V
0V
E2 M2
E20
M20
6A02
6A04
6C02
6C04
S6
M2
Detector
Detector
toggles between 0 and -48VDC
-48V
(e.g. American signalling)
S6 S7 S8
1 2 3
on
This switch setting is used
for signalling on E1 and M1.
1 2 3
on
S6 S7 S8
This is the switch setting when
E1, E2, M1 and M2 are used for
signalling.
Switch settings
Double E & M signalling
Standard E & M signalling
Applies for switches 109, 209, 309 and 409.