How Trigger Interval Settings affect image transmission in Ltl Acorn 2G Cellular Cameras

Fig 1: 6210 Wireless PCB and SIM900 Modem

This post is an explanation of how the interval time setting in the cameras menu affects the transmission of image data over a 2G cellular network.

This does not apply to the 6310 cameras with 3G modems when working over a 3G network, which were introduced at the end of 2016.

Acorn cellular cameras use the SIM900 GPRS 2G modem which can connect with either the GSM or the GPRS service. It is a class B device which means it can only use one or the other at a given time. During GSM service ( voice call, SMS and MMS ) the GPRS service is suspended, and then resumed automatically after the GSM service has concluded. 

Acorn cellular cameras utilise the SIM900 wireless modem to provide GSM ( SMS and MMS ) and GPRS ( internet access for sending an image in an email using SMTP ) functionality. 

In Acorn cellular cameras the SIM900 prioritises the GSM service when programmed by the user to periodically listen for SMS remote control messages. The SIM900 also prioritises the GSM service in response to a trigger

MMS Signal strength and External Antennas

Ltl Acorn 6210MMX

The general consensus is that these cameras need three to five bars to operate reliably and a high level signal requirement is stated in the manufacturers manual. In operation they are much like mobile phones in that environmental and atmospheric conditions can cause the signal to disappear erratically; and particularly in the case of these cameras, if this happens at the moment the camera is trying to send, it's lost until the next time.

The location and distance of the cell mast, obstructions in the form of buildings, trees and other vegetation, plus atmospheric changes at night and day interface, will all make a difference.

I operate in a mountainous area from about 5 to 15 km from the cell tower and over all of it, it's mostly impossible to get a workable signal; and at frequencies around a 1000 to 2000 MHz, signals bounce of buildings, rock faces, foliage et.c to further compound the situation.

MMS Connectivity with Ltl Acorn Trail Cameras

A lot of confusion surrounds the MMS set up of the Acorn trail cameras and although I don't profess to be an expert myself, I've done some research to try and identify why so many people seem to be encountering problems.

Post Update 12.12.2012 : Practical set up instructions for proven SMTP service which works with all Acorn Wireless Trail Cameras. 

A common theme seems to be an inability to get the camera to send to an email address.

Below I've shown all the connection settings for using the various Vodafone services as an example. To send an email from the trail camera make sure you are using the correct APN (Access Point Name) and also using an SMTP (Simple Mail Transfer Protocol) which allows authentication.

You may be having other problems and as soon as I can I will try and unravel some of the mysteries. My immediate problem is that I don't have reliable network access at my location and don't use these services; but I will very soon be making tests in a good signal area to try and clarify these issues.

In the meantime I hope that the information below is at least helpful.