Key features
Real time: The Open AT OS provides fixed guaranteed response time to external (through dedicated external interruption pins) and internal (DSP, hardware timer, SPI...) interruptions - not only when the GSM stack is off, but whatever state the embedded wireless module is in (idle, voice call, GPRS transfer...).
Pre-emptive: Host (customer application) tasks can have higher priority than non-critical Sierra Wireless GSM tasks.
Multi-task: Define as many tasks as you need for your programs. The Open AT OS uses semaphores to synchronize tasks.
VariSpeed: In order to tailor the available processing power, VariSpeed enables your application to dynamically switch the CPU Clock from Standard Mode (26 MHz) to Boost Mode (104Mhz). Switching instantaneous between the two modes will allow you to make the wireless module’s behaviour suit your application’s needs.
VariPower: VariPower uses clock-frequency variation to react to the limitations of an application’s autonomy when operating with a battery. It is possible to choose between several modes of energy saving.
Memory Access Protection: Specific memory areas (volatile and non-volatile) are allocated to the application on one side and to the firmware on the other. The Memory Access Protection feature will prevent rogue memory access to unauthorized memory areas.
Watchdog Protection: When operating in stand-alone mode, any field device must be monitored by a watchdog to avoid dead end lock software resulting in a frozen product. The watchdog provided by Sierra Wireless can monitor the firmware and the application independently.
Back Trace: Security mechanisms are implemented in the Open AT OS in order to protect the wireless module against software exceptions. When errors occur, the main reason is stored in a Back Trace. This information can be retrieved by the application and sent over the air for root cause exploration and post mortem debugging.
Open Audio Path: Although M2M applications usually use data channels, having full control over the audio chain can be very useful. Therefore, Sierra Wireless has opened the Audio Path to let you do whatever is requested for your solution - from Audio sniffing, playing and recording to equalizing.
DTMF generating and decoding: Not only will the Open AT OS allow you to generate DTMF - it will also allow you to subscribe to the DTMF decoding feature. This feature will allow the application to be notified by the Open AT OS when a DTMF on the microphone path or on the GSM audio channel is detected. You can even ask the wireless module to generate a DTMF and to detect some at the same time to test your audio chain.
Audio Chain Control and tailoring: The Open AT OS allows you to tailor the different audio filters of the embedded wireless module to ensure perfect sound rendering as well as full customization of the Echo Cancellation Algorithm.
Open SIM access allows you to connect a Sierra Wireless embedded module to your SIM server on any physical bearer (UART, SPI, Parallel...), using any data transmission protocol (PPP, IP, Proprietary...).