Foundation Fieldbus Linking Device

LD is a highly compact gateway between four Foundation Fieldbus (FF) H1 links and FF HSE suited for redundant use. The Linking Device is DIN rack mountable. It is powered by 24 V dc and supports Ethernet 10/100 Mbit/s.

LD serves as gateways between the field devices on the H1 links and the HSE subnet. The FOUNDATION Fieldbus subsystem consists of Linking Devices and possibly other HSE devices which communicate with one another using the HSE protocol and subsidiary H1 links.

In redundant systems, the corresponding H1 ports of both physical Linking Devices making up one redundant Linking Device are connected to the same H1 link. Both physical devices belonging to a redundant set are connected via a serial bus for exchanging redundancy control information.

CLD (Controlling and Linking Device) is a LD with FBAP engine and can run all FBs supported by PPC. Deploying advanced control algorithms on the CLD while running the input/output FBs on field devices makes it possible to have the best of the two worlds: Control in the Field + Advanced FBs. In this case the controller Function Block (e.g Auto tuning PID) is not deployed on a device which is physically located in the field, but on a device which is on the same H1 segments (the CLD) that other field devices participating in the control strategy are located. Thus all the benefits of the CIF are realized in addition to eliminating its drawback of being restricted to use only simple control FBs of the field devices.