in reply to: Re: HART Multi-drop network posted by Romilly on 11 July 2013 at 10:57:04.
The HART/Ethernet Gateway we are using is the Endress-Hauser FXA 520. It claims to support 30 HART device across 2 channels. The field devices used are HART enabled Electromagnetic flow meters and conductivity meters from the same manufacturer.
All the HART devices/gateway conform to the rev. 5 specifications
Over the past 10 days, we have been able to connect approx. 18 HART device(9 in each channel) and we are currently testing its reliability.
The loop current and voltage in a single channel is around 37mA and 9V respectively.
The total length of the cable is 1550 ft.
We are using a 2 core 1.5 sq.mm shielded cables.
Regarding the power supply, all the devices are powered externally i.e. it is a 4 wire system rather than the 2 wire system. So I don't suppose there will be a case of insufficient power in the loop.