Standard Horizon GM29 manual Audio Connector, Vcc, Hrin, Toin, Gnd

2. ELECTRICAL DESCRIPTION

The power connector electrical characteristics are listed below:

Pin	Signal	Dir	Limits	Description
1	VCC	I	5 - 32V	Positive power input
2	-	-	-	No connection
3	HR_IN	I	–0.5 - 32V	Active high control line used to switch
				off or reset the modem
				VIH > 5V, VIL < 2V
				Power off: 1s < t < 2s
				Hard reset: t > 3.5s
4	TO_IN	I	–0.5 - 32V	Active high control line used to switch
				on the modem
				VIH > 5V, VIL < 2V
				Power on: t > 0.2s
5	-	-	-	No connection
6	GND	I	-	Negative power (ground) input and
				return path for TO_IN and HR_IN

2.2 Audio Connector

A 4-way RJ9 connector, as shown below, allows a telephone handset to be plugged into the modem, giving access to the microphone and earpiece signals. The connector may also be used to drive other analogue audio sub-systems or devices.

Although the GM29 is pre-configured to work with a range of handsets, the audio interface is flexible and its performance can be configured, using AT commands, to match a particular handset or audio subsystem.

4 3 2 1

1	MICN	3	BEARP
2	BEARN	4	MICP

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