Foundation field bus

  • Thread starter Shailesh C Patel
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Shailesh C Patel

i want to know that when i do commissioning of foundation fieldbus loop, what communication will be happen between processor and new FF device
without tag no?

I want to know that how processor can communicate with FFdevice with out any addresses?
Is any serial no like mobile' IMEI no?

Shailesh C Patel
A unique feature among Fieldbuses is that FF has automatic address assignment. That is, you need not configure and address using DIP switches. Nor do you need to connect the device by itself to a handheld or laptop to set an address. It is possible to simply take a device off the shelf, connect it to the wire, and the system will assign an address to it.

FF devices always have some address, somewhere in the range 16-255

The term "commissioned" is not used in FF specifications, but it is usually taken to mean that a tag and operational address has been assigned to a device.

There are two aspects to "commissioning"
- what happens on the bus and in the device (as dictated by the protocol)
- how it appears to the user (different for each system in the market)

Addresses 248-251 are "default" addresses used for devices which have not had their proper address assigned yet. However, this is only four addresses, and it is possible that somebody connects maybe 8 or even 16 decommission
devices and then turn on the power. Therefore most systems use additional addresses to identify decommissioned devices. In SMAR SYSTEM302 address 232 to 247 are "decommissioned". In SYSTEM302 address 16 to 47 are "commissioned". Other systems use different address ranges, but the scheme is the same.

When a device is connected to the FF bus the system will detect it. Usually the address is left as is, but if there is an address conflict with an existing device, this is resolved by changing the address of the new device to something else.

Address resolution conflict is possible to resolve because each device has a unique ID, which is an hardware address just like the GSM IMEI and Ethernet MAC like you mentioned.

To learn more about commissioning, take a look at chapter 3 of the yellow book "Fieldbuses for Process Control: Engineering, Operation, and Maintenance" buy online:

Jonas Berge
[email protected]
Learn fieldbus and Ethernet at your own pace:
Learn OPC and automation software at your own pace:

Verhappen, Ian

Each FF device has a unique identification that is a combination of its manufacturer ID, Device type, and manufacturer serial number. This identification is used at start-up until you assign it a tag that is more meaningful to you - normally the tag number as per the P&ID.

More details can be found in the technical overview and engineering guide on the Fieldbus website at

Ian Verhappen