I have created a small product using Sim800 and the product uses only GPRS. I am told by the testing company, that I need to create a test firmware which will continuously transmit.
The confusion is, that in order to continuously transmit, I need to know which IP and port to connect, but the testing house says, it will be simulated…and I don't understand what does that mean.
Even after 3 calls, the testing house keeps repeating the same requirement.
Maybe, either I'm not asking the right question or the testing house is not giving me right answer.
Therefore, the exact question is – I need to write a firmware which will use AT commands of Sim800, connect to the internet and simply ping a website in a loop. Since this will be inside a simulator, what IP/Port combination is required OR how is this simulated.
The testing house does not say anything and is not very co-operative in this regard.
Any pointer in this area would be of great help.
Best Answer
The "continuous transmission" requirement cannot be met with regular HTTP requests, you are expected to use every GSM slot, ignoring any higher-level protocols.
This test verifies that the emission spectra are within required parameters; this is done by moving a bandpass filter across the spectrum and writing down the power of the signal received. As moving this filter requires some time, the signal must be present for the entire duration -- interruptions could hide problems.
You are still required to follow the GSM framing and disable the amplifier between packets to verify that the sharp transitions at the packet boundaries do not translate to transmissions outside the allowed range.
The module is already approved as far as I know, so there is most likely a non-functional testing variant of the firmware that was used in that certification, so you'd have to ask the vendor for either a copy of that firmware, or a pre-flashed module that can be used for verification.