Almost half of the billion-plus pneumatic valve blocks sold globally last year included a networking facility. But, according to a new report from IMS Research, for every block networked with an Ethernet-based protocol, nine were networked using a "traditional" fieldbus.

Closed-loop communications and intelligent feedback have become increasingly desirable for pneumatic set-ups, allowing engineers to cut air wastage and to provide system monitoring and diagnostics. However, the absence of an industry-standard network protocol, leaves them with many options for communications, ranging from supplier-specific proprietary fieldbuses, to Ethernet TCP/IP.
 
“In 2010, Profibus was used for over a quarter of all valve block networking applications, and DeviceNet for almost a fifth,” reports IMS research manager, Rob Carter. “These two supplier-championed fieldbus protocols are currently each more prevalent than the combined variants of Ethernet which account for a total of only 14%.
 
“The additional complexity of Ethernet variants far outweigh the advantages of its higher-speed communications in pneumatics systems, where actuation speeds are determined to a greater extent by air flow rates,” Carter points out. “The comparable simplicity of many fieldbus protocols makes this a more desirable option in most standalone systems, limiting Ethernet’s use to instances of large-scale networking from factory-floor to control-room.”
 
According to IMS, the global market for pneumatic valve blocks grew by 18.4% last year to reach $861.5m. It expects Ethernet to remain the fastest-growing networking protocol for pneumatic valve blocks, but by 2015 it will still account for only 18% of global pneumatic networking applications – leaving it far behind fieldbus technologies.