ICM-400 Series Intercom Stations
Page 4
Document IM-ICM-400-2.14
Aud +
Aud -
Aud -
Aud +
1
2
3
4
10
9
8
6
7
3
2
5
4
1
4
3
2
1
4
3
2
1
Switch B In +
Switch B Out -
Sw B In -
Switch B Out +
Switch A In +
Switch A Out -
Switch A In -
Switch A Out +
SWB
-
-
+
+
-
-
+
SWA
+
CN1
CN2
CN3
CN4
Spkr +
Spkr-
4.50"
4
.50"
2001 Harding Instrument Co. Ltd.
PC06713-04
Rear View of ICM-420 Printed Circuit Board Showing Header Positions
Header CN1 is always present.
Header CN2 is not present.
Connector CN3 is present if the option allowing Switch B to switch an external device is ordered.
Connector CN4 is present if the option allowing Switch A to switch an external device is ordered.
3.1 Audio Connection from System to Intercom Station
Each intercom station is connected to the exchange with a single shielded twisted pair. This pair is connected to
terminals on the field interface terminal block. In turn these terminals are connected via a twisted pair in a CBL-
190 cable to the SAB-400 (or SAB-401).
All shields are terminated at the field interface teminal block. The shields are grounded through the cable that
connects the terminal block to the DB-37 connector on the SAB-400 (a CBL-190 cable). Note the CBL-190 cable has
3 wires that are connected to ground on the SAB-400/401 (See IM-DXI-REF-MAR05). The shields are left open at
the intercom station end of the cable. Where two twisted pair cable segments are used to make up a cable the
shields must be continued from one cable segment to the other. Care should be taken to ensure that the shields on
the different signal pairs are not connected together, except at the terminal block.
The connections to the intercom station are made with an AMP MTA-100 series connector. The intercom pair
should connect to pins 1 and 2 on a female 4-pin AMP MTA-100 series connector that plugs onto the header
labeled CN1 on the printed circuit board of the intercom station. To make these connections you should use an
AMP Handle Assy 58074-1 tool with a 58246-1 head. The cable should be cut to length and the shield and outer
