First I think I should point out that Profibus-PA instruments do not use RS-485 (such as is used by Profibus-DP), but a MBP (Manchester Coded, Bus Powered) physical layer, as described in the IEC 61158-2 standard.
This is why you need a bus coupler to 'translate' the signals from Profibus-DP to Profibus-PA, and to power the PA bus.
The maximum transmission rate of Profibus DP network 12Mbps
The maximum transmission rate of Profibus PA network 45.45Kbps
You need to power the DP instruments, while PA instruments get its power and exchange data via the same PA cable .
You need DP/PA link or DP/PA coupler to link DP network with PA .
when you use a coupler connected directly to the DP network , then your DP network transmission rate would be decreased to 45.45.
Both Profibus(PA) and FF H1 started off in the same working group and have much in common: the physical medium on which both operates is in accordance to IEC 1152-2 intrinsically saftey. Profibus DP which is used in 90% of profibus applications use either RS-485 or an Optical fibre link. When comparing thir implementation on the data layer in Profibus the input and output blocks are located in the controller itself. The controller(master) fetches the data from the field instruments. However no control blocks are moved into instruments. In FF, the input blocks along with the control block are moved into instruments consequently implementing 'control in the field'. The number of devices per segment/loop also varies in Profibus VS FF H1, with the later having a max of 127 and being limited to 32 due to bottleneck of RS-485 and FF to 31 itself. But practically FF system recommends no more than 12 devices per loop with a cycle time of 0.5s while profibus supports 24 with a delay of 400ms.
What is PA what is PAC in doctor terms
PA is an abbreviation Pennsylvania while MI is an abbreviation for Mississippi.
well darling, an md is an mc donalds and a pa is a poached apricot.
what is the deffrent between pa-xt and pc-at
The time difference from AZ to pa is 2 to 3 hours
Philadelphia, PA is 3 hours ahead of Phoenix, AZ.