A modem (modulator-demodulator) is a device used to transmit and receive digital data over an analog communications channel. Common examples are PC modems that use an analog telephone line and wireless modems that use RF (radio frequency).
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GPRS modem gets struck/hangs up when “AT” is entered
I started working on a U-blox LEON-G100 gprs modem connected to the PC terminal through UART. Whatever character I enter into the terminal gets echoed back except "AT". When I enter "AT", the modem ...
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Modem hang-up time
I'm looking for some typical and worst-case times for a serial modem to hang up and DCD deassert after receiving the hang-up command string ("ATH").
My project uses a modem and occasionally must ...
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217 views
Establish connection between analog and GSM modem
I want to know if I can call a GSM modem (a SIEMENS MC55) from a normal analog (PSTN) modem. If so, how do I have to configure the GSM and the analog device? I've read about the +FCLASS and +CSNS ...
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No response from device using half-duplex modem connection [closed]
We are facing a tough problem on half-duplex (analog / PSTN / V.23) modem connections. We are using this method to communicate with aged meter devices which are located all over the country. We are ...
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861 views
How to connect ADSL router that takes RJ11 as input with cable which is RJ45 [closed]
Actually i have a Wireless N ADSL2+ 4-Port Wi-Fi Router with modem and it takes RJ11 as input for internet, but my Provider cable is RJ45 and i want to use wi-fi. so how could i will be able to do ...
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Serial Adapter in DCE mode
I'm developing software for a device that will act as a modem emulator. In order to test it out, I need to have a serial port that is capable of operating in DCE mode (e.g. is able to toggle the modem ...
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373 views
How to build a telephone answering machine with caller id
I'm brand new to electronics. I'm interested in building my own telephone answering machine with caller id receiver from scratch as a learning project. How would you suggest I get started?
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Sniffing ADSL data exchange
I would like to capture and decode the ADSL traffic going on between my modem to the CO equipment.
I am thinking of a setup similar to the one shown in this paper, but it seems the necessary hardware ...
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187 views
Performance Analysis of PLC Modem
I'm an electronics and communications engineering student undertaking a project regarding the occurrence of Electromagnetic Interference (EMI) in power line communications (PLC).
I would like to ...
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3answers
430 views
56k Single Chip Modems
I'm currently working on a project that's intended for getting old electronics that access networks through the use of a phone line to access the internet. To do this, I'm emulating a simple phone ...
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345 views
Typical GSM current profile
I'm working with GSM modem and I'm wondering if anyone has come across any sort of measured or typical GSM current profiles for various actions such as:
Connecting to base station
Sending a SMS
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623 views
Awesome modems with Arduino compatibility?
I'm looking for a modem that can hook up to the input port on a portable ham radio and an ardunio board serial connection. Not really interested in APRS, it's too high level for my needs (long ...
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Power line communication, how to check if frequency is present
I'm trying to communicate on a power line without external filters (only a filter for the 50/60Hz), because I want to use only digital filters.
My processor is a Cortex-M3 device running at 24MHz.
...
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152 views
New to Electronics: How to connect these sparkfun sensors to this radio?
I'm really new to this electronics thing, but I was curious how to connect this High Altitude Balloon sensor board to this modem. I want to think that it will connect easily and that the hardest part ...
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Best method for sending data over a mono audio channel
I'm looking for a way to send binary data over an audio channel on a video/audio transmitter. This will be an add-on feature to my product because it already has an audio interface. I'm hoping to be ...
