However, the data transfer by this interface has to be located close to the controlling PC, because RS232 is designed for short distances only. Beyond, the PC has to be dedicated and opts as master.
With a multiport interface in the PC several instruments can be controlled in parallel. To overcome these limitations – distance and dedication – instrument manufacturer have discovered the potential of Ethernet-LAN-interfaces and started to implement it into their analysers.
Each instrument receives a designated IP number and the communication from every user in the network through the RJ45 UTP ethernet cable can be accomplished (Fig.1). Different user may not simultaneously access the same instrument, but sequentially with the big advantage not to be limited to a dedicated PC.
Beyond there is an additional advantage: External support from anywhere in the world can access such a specific analyser provided the LAN administrator allows the passage through the firewall.
Many new intelligent instruments such as the ECO PHYSICS series CLD60 or the modular CLD800 series NOx analysers will be included into a local network, because they offer already today an RJ45 LAN connector – many more analysers will follow this path!

ECO PHYSICS is based in Dürnten, Switzerland. www.ecophysics.com