User guide
Table Of Contents
- Guarantee
- Contents
- CS-GPRS Communications Package
- 1. Introduction to GPRS
- 2. Hardware
- 2.1 Power use considerations
- 3. Network Contract and SIM card
- 4. Datalogger firmware
- 5. PC Software required
- 6. Basic Datalogger setup
- 7. General Principles of Operation
- 7.1 Using systems with fixed, public IP addresses
- 7.2 Using systems with dynamic IP addresses
- 7.3 Keeping the connection open
- 7.4 Firewall issues
- 7.5 Minimising call costs and power use
- 7.6 Calling the logger in GSM data mode
- 8. Fault finding
User Guide
3
For full flexibility specialist suppliers provide a service to give individual devices
a fixed IP address, which can either be private, e.g. accessed via a VPN
connection, or a public address on the internet. In the UK one such supplier is
Wyless.net. Such companies are suitable for larger scale networks and provide
additional on-line tools to let you monitor the state of your GPRS connections,
traffic use etc. Currently Campbell Scientific Ltd does not resell these services
nor can they provide support for the setup and running of the service.
It is important to ensure you are aware of the likely costs of GPRS data transfer.
Prices can range from £0.005 to £10.00 per Megabyte of data transferred. As it
can require in excess of 50 Kbytes of data per day to check and keep a GPRS
connection open, let alone transfer any data, it is important to find the right tariff
and realise the likely costs. Where an always on connection is required a flat-rate
tariff will likely be more economic or you should at least negotiate a volume
discount tariff with your provider. In the UK it is now possible to buy data only
access for around £15 for up to 36 MB per month.
Before using the system you need to know the APN server name of your provider,
plus your username and password to gain access to the GPRS IP services.
4. Datalogger firmware
GPRS modems require support for PPP (point to point connection protocol) which
is currently available for the CR800 series, CR1000 and CR3000 dataloggers (not
the CR200, CR5000 or CR9000X).
The most reliable release of fully tested code is in release 15 (or later) of the
CR1000 operating systems (and partner CR800 and CR3000 versions) released in
January 2008.
5. PC Software required
The logger connects to the network using a PPP login (Point to Point Protocol). To
configure the PPP settings in the logger the CS Device Configuration program
version 1.8 or later is required. The latest version can be obtained from
www.campbellsci.com/downloads
It is also included in Loggernet 3.4.1 which
includes support for some of the CRBasic instructions added relevant to TCP/IP
and PPP. Please check for later updates on the download site and/or contact
Campbell Scientific for further details if you need to use these.
6. Basic Datalogger setup
You need to connect to the datalogger using the device configuration utility and
enter several settings to match the GPRS service that you have.
Firstly you need to select the serial port to which the modem will be connected,
e.g. RS232, COM1..4 or CS I/O ME or CS I/O SDC (for the CS I/O port). Select
CS I/O - SDC7 to use the SC105 in its default configuration.
The speed at which the logger talks to the SC105 is called the SDC Baud rate and
is normally fixed and does not have to be changed.
If using another interface it is then necessary to fix the baud rate for the serial port
that the modem is connected to. This is done using the Port Settings tab. Set the
baud rate for the relevant port to a fixed baud rate which matches fixed baud rate
programmed in the manual. As a starting point set both to 9600 baud. Higher