in reply to: Re: Re: Fieldbus cable Specification posted by pravin raut on 15 December 2009 at 07:30:09.
The Fieldbus Foundation H1 fieldbus cable specification is FF-844. This is based on IEC 61158-2. (Full specs are available from these organisations.) Two grades are specified: type A (best) and type B. There are several important enhancements to normal signal cable specifications like BS5308. The main features of Type A (recommended for new applications) are specified impedance (100 ohms +- 20% at 31.25kHz), attenuation (3db/km max at 39kHz), and capacitance unbalance (4nF/km max).
See also http://www.romilly.co.uk/wwwboard/messages/1830.htm.
You might also be interested in http://www.fieldbus.org/images/stories/international/asiapacific/India/presentations/cabling_solutions_for_ff.pdf and http://www.analogservices.com/cable.htm .