Profibus PA VS Fieldbus

L

Thread Starter

Lewiss

I need information about Profibus PA. Electrically Fieldbus and Profibus PA are the same (Same speed, Same encoding, Same signal).

I am familiar with Foundation Fieldbus, my question is about when adding a new device on bus live. I know in Fieldbus the new device added will get an temporary address from the host and you have to commission it with a permanent address in your network. All the other device in the network will not be affected by the adding of this new device. But I don't know the way to do it in profibus PA. Somebody told me we have to shutdown the network and put it back on to be able to use a new device on a bus. I need to validate this.

If anybody could provide me information about this or give where I can get this information I will appreciate.

Thanks in advance.
 
J

Jonas Berge - F

With Profibus PA (and DP) you must assign the address to the device before you hook it to the network. This can either be done using a DIP switch or by connecting a laptop with interface and coupler to the device point to point and setting it from software. Then you can connect the device to the bus. FF is a bit easier since the addressing is automatic.

I don't see why the PA bus must be shut down though. Perhaps this is vendor specific? Different systems or interface cards and software could be different in this respect.

If you are comparing FF-H1 vs PA there are a few other points apart from addressing you could look at:
. H1 is Isochronous
. H1 is Peer-to-peer
. H1 is Publisher/subscriber
. H1 has Clock synchronization
. H1 has Alarm & event reporting
. H1 supports firmware download

Technological differences ultimately translate into differences in the benefits provided in terms of:
. Performance
. Ease of support
. Predictive maintenance
. Ability to stave off obsolescence
. Easy integration

To learn more about these differences take a look at the yellow book "Fieldbuses for Process Control: Engineering, Operation, and Maintenance"
buy online:
http://www.isa.org/fieldbuses

Jonas
 
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