The universe of industrial electronic temperature controllers equipped with communication bus/network connectivity will increase significantly, according to a recent Venture Development Corp. (www.vdc-corp.com) study.
In a survey that includes end users, OEMs, and system integrators, VDC determined that less than half of microprocessor-based, single-loop controllers and only 55% of multiple-loop controllers purchased in 2002 have communication bus/network connectivity. By 2005, these shares are expected to increase to about 64% and 72%, respectively.
The survey results determined that standard serial interfaces are used extensively in North America, but are expected to give way to other types. Among North American users in the survey, RS-232 is the most used communication bus/network with the microprocessor-based, single-loop temperature controllers purchased in 2002. RS-485 accounted for the second largest share, with Ethernet third. These users indicate that Ethernet will overtake RS-232 and RS-485, and account for the largest share in 2005.
RS-232 also is the most used communication bus/network with the microprocessor-based, multi-loop temperature controllers purchased in 2002. However, in this case Ethernet already accounts for the second largest user share, and is expected to account for the largest share in 2005.
Foundation fieldbus is much more extensively used with microprocessor-based, multi-loop controllers compared to single-loop controllers and is expected to account for the second largest share in 2005.
Use of wireless connectivity is expected to grow and account for the fourth and fifth largest shares respectively for single and multi-loop controllers in 2005.
While Ethernet is an international standard, it specifies only the physical and data-link layers of the Open System Interconnection (OSI) model, so in actual use, additional protocols are required. Among the North American users in this survey, TCP/IP was identified as the most used network and transport layer protocol, with Ethernet/IP as the most used application layer protocol. The survey results indicate they are expected to remain the most popular in 2005. HSE, SMTP, and XML application layer protocols are projected to gain acceptance and wider use between now and 2005.