The three connection types: Fieldbus module for SFC systems (A), external converter for wall mounting in the enclosure (B) and mounted on a DIN rail (control cabinet installation) (C).
The measuring and control devices currently support three of the standard fieldbus communication protocols. These are Profibus DP and Profinet IO, which are more common in Europe, and Modbus TCP, predominantly used in the USA. Implementation of the fieldbus connection varies according to the type of device.
For SFC systems, the optional fieldbus module is integrated inside the systems’ enclosure as a piggy-back electronic board or can be retrofitted later. For MFC and Depolox Pool systems fieldbus converters are available that can either be DIN rail mounted for incorporation in a control cabinet, or in a separate external enclosure. Retrofitting is also possible here at any time. The device connected to the fieldbus is detected automatically by “Plug & Play”. Fieldbus parameters can be assigned in the measuring and control system’s user menu. The parameters involved depend on the fieldbus system: for Profibus, it is the bus address, for Profinet, the device name.
In the past, measuring and control devices were always connected to a PLC via a 4-20-mA interface. This caused additional wiring and programming. Through the fieldbus communication, the PLC can access a larger number of process parameters, such as measured values with units of measure, dosing rate, flow rate and status of digital inputs and relay outputs. Setpoints, limit values and control parameters can also be read and written from the PLC.
Further information under: http://www.siemens.com/wallace-tiernan
A photo supplements this press release. Please see:
http://www.industry.siemens.com/data/presse/pics/IIS200906720.jpg