User's Manual

Chapter 11 – SocketModem EDGE (MTSMC-E)
Multi-Tech Systems, Inc. Universal Socket Hardware Guide for Developers (S000342D) 138
Pin # Signal
Name
In Out
Type
Description
39 –DCD O
Data Carrier Detect (Active Low). –DCD output is ON (low) when a data
connection is established and the module is ready to send/receive data.
40 –DTR
I
Data Terminal Ready (Active Low). The –DTR input is turned ON (low) when
the DTE is ready to communicate. –DTR ON prepares the modem to be
connected, and, once connected, maintains the connection. –DTR OFF places
the modem in the disconnect state under control of the &Dn and &Qn
commands.
Note: When the –DTR pin is not in use, it should be tied low.
41 GND GND
Ground
42 SPK– O
Speaker. Negative analog speaker output.
43 SPK+ O
Speaker. Positive analog speaker output.
58 LED
LINK
O
LED LINK (Active Low). LED Output. During normal operation, this pin lights
the LINK LED to indicate a good link is detected. See LED Mode Table below.
61 VCC PWR
DC Input Power. 3.3 V or 5 V DC power, depending upon the build.
63 GND GND
Ground
Pin 58 – LED Mode
LED Mode – Pin 58 Operating Status
Off SCME is off or run in SLEEP and Alarm modes.
600 ms ON / 600ms OFF No SIM card inserted or no PIN entered, or
network search in progress, or ongoing user
authentication, or network login in progress.
75 ms ON / 75 ms OFF / 75 ms ON
3 s OFF
Flashing
One or more GPRS contexts activated.
Indicates GPRS data transfer: When a GPRS
transfer is in progress, the LED goes on within 1
second after data packets were exchanged. Flash
duration is approximately 0.5 s.
ON Depending on type of call:
Voice Call: Connected to remote party.
Data Call: Connected to remote party or
exchange of parameters while
setting up or disconnecting a call.