Freelance 800F provides an OPC gateway (server),

which allows OPC clients to access data and alarms

from the Freelance process stations. From Version

.1 upwards, the OPC server also allows access to

the DPV1 parameters and user parameters of

PROFIBUS and HART devices. In the case of HART

devices, this is only possible if they are connected

to a S900 unit. For V8. and higher, the parameters

of FOUNDATION Fieldbus devices can also be

accessed. It is possible to limit access to this data

at the OPC gateway such that an OPC client cannot

see certain process points and variables at all, can

only read other process points and variables, or has

both read and write access to certain

process points and variables.

The DigiVis operator station has a built-in OPC client,

which permits you to access data from external

OPC servers. Using this, for example, data from a

SIEMENS control unit can be integrated into a cus

tom graphic in DigiVis.

As several OPC gateways can be used in the Free

lance system, server redundancy can be established

using OPC clients that support this function. * The

Control Builder F engineering software supports this

with the redundant OPC gateway configuration.

The trend server option provides a special OPC

gateway that is used by the DigiVis operator stations

for user-defined trend displays. Access to the trend

server is fixed to “read only”, and all trend variables

are automatically available. There is one trend server

per Freelance system.