EASY GPRS DATA LOGGER (EGDL), GPRS programming

Transcription

1 EASY GPRS DATA LOGGER (EGDL), GPRS programming This section is valid only from firmware GTM 868/5.01/V2/xxxx In this section it is explained the functioning, programming and the description of the GPRS technology used by Gemini (GTM 868). The General Packet Radio Services (GPRS) standard permits DATA transfers in a completely different way with respect to previous point to point communications made with Circuit Switch Data (CSD) GSM modems. In CSD operations the modem establishes a connection with the other party (another modem) in such a way that a1l the Network devices in between are transparent to the data exchanged, simulating a real point to point connection, just as if the other party is directly connected with the controlling application of the modem. The other party can be either an Internet Service Provider (ISP) or a private server, but in any case, the arrival point must have a modem to connect to (landline, ISDN or GSM CSD). The connection establishment procedure defines a particular path where all the information exchanged between the two peers flows and this path is reserved for exclusive use of these 2 peers for all the time the correction is active. This approach has the drawbacks of a long time to set-up the link between the two peers (up to a minute) and a time counting bill which proceeds even if no data is exchanged because the path resources are reserved anyway; furthermore the speed of the data transfer is limited to bps. An example of this kind of operation is shown in the following picture, where the point to point connection is between the two peers as if all the devices inside the dashed lire are not present: 1 Document version :

2 In GPRS operations instead, the connection is made directly towards internet as if the GPRS modem was a network IP socket interface. There's no data path reserved for the data exchange between the two peers, instead the resources are allocated dynamically on demand and the data exchanged is organized into packets typically TCP/IP, furthermore the maximum transfer speed can be much faster than GSM CSD. An example of GPRS connection is shown in the following picture, where the GPRS connection is between the GPRS modem and the internet as if all the devices inside the dashed line are not present: Due to this kind of connection, when activating the EASY GPRS DATA LOGGER (EGDL), you must provide the network parameters enabling the EGDL to enter through the internet point of the GPRS network. Therefore, the EGDL does not establishes a direct point to point GPRS connection between two modems as in CSD case, instead it established an internet tunneling in order to achieve a point to point correction between two peers. This approach as the immediate advantage of projecting the controlling application of the EGDL directly on the internet, ready to be accessed virtually train anywhere in the world at the same cost on the GPRS; actually the billing of the GPRS connection is based on the amount of data exchanged (number of packets transferred) independently front the time the connection is active or where these packets must lie delivered. Therefore, it is possible send data from the EGDL to the AXELPROD server on demand, while paying only for the data really sent. As said, all the data are sent from the EGDL (GTM 868 or GEMINI) to AXELPROD web server (upload) in order to collect all data from all GTM modules around the world.. AXELPROD engineers have developed web assistance showing all your data on tables, curves and downloadable files. The customer has the opportunity to subscribe to this service through AXELPROD web site: under GTM Network. 2 Document version :

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4 EASY GPRS DATA LOOGER (EGDL) programming The GPRS setting must be programmed with the information provided by your operator, therefore for any information, please refer to yours or refer to under support/download/general information/gprs setting for various network operators. Please note that this list of information is not updated automatically. Everything the user has to program for the GPRS setting is the following: APN: Access Point Name. Ex: gprs.swisscom.ch IP: usually USERID: User Identification, usually it is empty. USERPASSW: User Password, usually it is empty Everything the user has to program for the EGDL is the following: - Selection of the inputs-outputs - Measuring interval (1 to minutes) - Upload interval. (time between two data transfers from GTM to AXELPROD server, 1 to minutes) - Message and phone number for upload successful (if needed) - Message and phone number for upload failed (if needed) 4 Document version :

5 Special SMS commands for SMS Application the EGDL IMEI REQUEST #CG? Request the IMEI UPLOAD ON REQUEST #XR The GTM module will make an upload with the data and continue to log. UPLOAD ON REQUEST #XR# The GTM module will make an upload with the data, erase the memory and start over from 0 Recommendation using EGDL As the GTM 868 (GEMINI) have no multitask but a single task processor, by SMS duty it is not recommended to use long delay time before and after sending SMS (#WA, #WD and #DA, #DD) It is highly recommended to make a GPRS test before doing any data logging process, do not try to do this process without successful GPRS test. The test is proposed in the new GTM programmer. V Document version :