Environdata’s communications options make continuous access to your weather data possible. Even if continuous access is not required, using a remote communications method eliminates the necessity to travel to the weather station site to download data. This means it is easy and cost-effective to collect data at optimal intervals.To select the best option for your application, you need to consider three main points:
- How often you need to update data
- Power availability at the remote site
- Capital expenditure versus running costs
A summary of each method is shown below. However, we recommend you also contact us for our professional recommendations.
1. Direct cable connection
This is the lowest-cost solution, suitable for distances up to 100 metres. Lightning protection is required. In some cases, it might not be practicable because of cable installation costs. Normally, the cable connects to the serial port of a computer, but can be connected to your local area network (LAN) via a Serial to Ethernet converter (XP10 series device). The cable also provides the opportunity to power the system from the office instead of using solar power.
2. Telephone Line
A standard telephone line can be used via either a mains powered or solar powered modem. This method is normally only cost effective if an existing line is available. The advantage of all standard telephone line or mobile telephone connections is that the weather station can be accessed from anywhere. However, line rental and call costs have to be considered.
3. Mobile Data Connection
This is similar to the standard telephone line, but with a higher call cost. Mobile coverage must be available at the weather station for the network and provider you choose. Both GSM and NextG networks can be used. However, the NextG network has a wider regional coverage area and is currently used more frequently for our weather stations.
Depending on the usage required, we can supply either the older style dial up connections, called Circuit Switched Data (CSD), or the newer Internet based connections, called Packet Switched Data (PSD). CSD is charged on a time-basis and suits lower cost applications where data is only required daily or less frequently, while PSD is charged on a data-basis and suits applications that require frequent or continuous data.
4. Radio Link
These can be used where telephone services are not available or as an alternative. All radio links require direct line-of-sight to operate, but repeaters can be used to solve line-of-sight problems. Short distance point-to-point radio links can be used over 1-5 kilometres distance and larger systems for distances up to 20 kilometres.
Generally, radio links have higher capital costs than mobile connections, but no call costs. This means the overall cost is less for long-term installations. The choice of system is dependent on the distances required, and the availability of mains power or solar power.
This is the most expensive option in both capital and running costs, but the connection speed and link reliability are excellent. This should be seriously considered for remote sites where access is difficult, and is still a very cost effective solution compared to expensive transport costs for staff.
6. MODBUS TCP/IP interface
The new MB40 MODBUS interface to our weather stations makes connecting our weather stations to industrial networks easier, by using a standard network (Ethernet) connection. This typically applies to SCADA, PLC and BMS systems without the need for low level programming.
The new design makes the most recent memory data available (Daily, Hourly and 10 Minute data) as well as ‘Current’ sensor readings. There is also provision for synchronising the weather station time clock where precise time matching is required. As well as the Ethernet (TCP/IP) interface, there is also a serial (RS485) communications option for applications where long cable connections are required (up to 1300 metres). Configuration can be set from DIP switches or via MODBUS registers or more easily via a web page for the Ethernet version.
MB40 is a standalone version that is suitable for DIN rail mounting , while MB45 is enclosed in the sealed housing of the weather recorder with access via a sealed gland.
In relation to the best communications option for your application, please contact Environdata for more information and technical advice.