The power connector electrical characteristics are listed below:

Pin

 

Signal

Dir

Limits

 

Description

 

 

 

 

 

 

 

 

 

 

1

 

VCC

 

I

 

5 - 32 V

 

Positive power input

 

 

 

 

 

 

 

 

 

 

 

2

-

-

-

No connection

 

 

 

 

 

 

 

 

 

 

3

 

HR_IN

 

I

 

–0.5 - 32 V

Active high control line used to switch

 

 

 

 

 

 

 

 

off or reset the modem

 

 

 

 

 

 

 

 

 

VIH > 5 V, VIL < 2 V

 

 

 

 

 

 

 

 

 

Power off: 1 s < t < 2 s

 

 

 

 

 

 

 

 

 

Hard reset: t > 3.5 s

 

4

 

TO_IN

 

I

 

–0.5 - 32 V

 

Active high control line used to switch

 

 

 

 

 

 

 

 

 

on the modem

 

 

 

 

 

 

 

 

VIH > 5 V, VIL < 2 V

 

 

 

 

 

 

 

 

Power on: t > 0.2 s

 

 

 

 

 

 

 

 

 

 

5

-

-

-

 

No connection

 

 

 

 

 

 

 

 

 

 

6

 

GND

 

I

-

 

Negative power (ground) input and

 

 

 

 

 

 

 

 

return path for TO_IN and HR_IN

 

 

 

 

 

 

 

 

 

 

2.2Audio 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 subsystems or devices.

Although the TT4031 (SE-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.

Owner’s Manual

Rev 1.0

Page 30 of 30