Open Wireless Standards for Interoperability
The ISA Wireless Compliance Institute has recently published the list of wireless devices now certified to ISA100.11a, which includes Yokogawa and Honeywell transmitters, plus the Nivis communication protocol stack. But as yet there is no news from ISA on the state of the revisions being made to the ISA100.11a-2009 standard that was withdrawn from the ANSI approval process because of errors. Pat Schweitzer, co-chair of the ISA100 committee, had commented at the Honeywell User Group in June that the corrections would be made and the standard re-issued by December, possibly therefore to be called ISA100.11a-2010. However, there is no clarity about the current certifications, in terms of which version of the standard ISA might be working to, which rather flies in the face of the "openness and interoperability" suggested to be prime objectives at the heart of ISA100. Hopefully the next few weeks will see the ISA100.11a-2010 version presented, at least before the compliant devices finally emerge from production. Yokogawa promised units in Q3.
In contrast, perhaps coincidentally, perhaps not, the Hart Communication Foundation has announced improvements to the published WirelessHART test systems, in the form of Wireless Test System v1.4 and Wi-Analys Software v1.3. These new versions provide manufacturers of WirelessHART devices with significant improvements in test performance, tool usability and technician productivity when compliance testing WirelessHART devices to the HART protocol requirements.
"The WirelessHART Test System plays a key role in ensuring the compliance and interoperability of WirelessHART devices," says Ed Ladd, director of technology programs at the HART Communication Foundation. "The WirelessHART test system is critical to the development of WirelessHART devices. Product developers and manufacturers use it to test their WirelessHART device implementation." This sounds remarkably like the sort of openness and interoperability that the ISA are aspiring to.