I'm sorry, but this kind of connection cannot work between the host and the devices. Actually, only 2 kinds of connections are available for FF communications.
1. Using NI-FBUS Interface Card
NI-FBUS interfaces connect FOUNDATION Fieldbus devices to standard personal computers: desktop, industrial, and notebook. These interfaces, which connect to H1 (31.25 kb/s) networks, are available in 1 and 2-port configurations. NI-FBUS CM (communications manager) software for Windows 2000/XP is included with each interface. Please refer to the following link for details.
http://sine.ni.com/nips/cds/view/p/lang/zhs/nid/10238
2. Using Ethernet and HSE (High Speed Ethernet) Linking Device
The HSE Linking Device acts as a bridge between the host and the device. It connects to the device through the H1 network and connects to the host through the Ethernet network.
Hope it helps!
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Josiane Zhou
National Instruments
Product Support Engineer for NI-FBUS