The Sun is a huge source of abundant power, sending nearly 10,550 EJ of energy to the Earth every day. This is more energy in one hour than all the combined cities of the world use in one year. To try and harness this magnificent power, many countries have been investing in solar technologies for over 30 years. Today's solar thermoelectric systems include reflectors, mirrors, heat insulating absorbers and advanced motion control technology. Advantech's own Industrial Wireless Ethernet products are a perfect fit for many such applications due to their great performance, reliability and ruggedness.
Wireless communications are an excellent complement to industrial wired solutions for many applications. In a typical solar thermoelectric control system, a combination of wired and wireless communications can effectively solve problems related to data transmission and field application issues. Two connection modes are supported; Infrastructure and Ad-hoc. When in Ad-hoc mode, the wireless network card does not require a huge network structure and a high-speed, simple network can be built without a lot of end-user effort. In this solar thermoelectric control system, the client required a wireless network with the following requirements:
- Industrial grade equipment with high electromagnetic compatibility
- Fanless products to operate in extreme environments with high temperatures and humidity
- Long MTBF
- Easy network management
||802.11b/g wireless AP/wireless bridge client
||1-port RS-232/422/485 to 802.11b/g wireless serial device
WLAN Access Points (AP) are very similar to an Ethernet switch. On one hand, each AP communicates with regular nodes (Clients) regardless if they are fixed nodes or mobile nodes. On the other hand, APs can connect directly to each other through a cable or an independent wireless network, thus realizing communications without the limitations of a wireless network.
This solution adopted Advantech's Wireless AP EKI-6311G and Wireless EKI-1351 Serial Device Server. 100 PLCs have been deployed in the field, and each PLC adopted Wireless mode to transmit information to the host computer. Moreover, these PLCs are far away from the central control room. Therefore, Advantech recommended to the ratio of 1 Wireless AP for every 10 PLCs to guarantee reliable wireless network transmissions. The Wireless APs apply WDS (Wireless Distribution System) technology allowing them to be bridged flexibly, making it easy to transmit data to all of the 100 PLCs through 100 EKI-1351's and them upload all relevant information to the central control room.
Composing a control system using wireless network modules has the following advantages:
- Simplifies maintenance while reducing maintenance costs and system downtime
- Provides remote diagnosis and maintenance.
- Solves the problem of carbon-brush wear and wire damage due to device rotation.
- Makes it possible to connect the device in highly corrosive environments.
- Saves the cost and effort of installing a complicated network of cables.
Advantech's EKI-6311G AP provides 54 Mbps high speed transmission rates, 128-bit WEP encryption, an IP65-based dust-proof and waterproof design and enhanced dual antennas, thus greatly improving wireless transmissions and building a reliable wireless communication platform in a rough industrialenvironment.