> Can anyone help me with the difference between PA and DP profibus?
Profibus-PA is specified by IEC 61158 Type 3. It is a manchester encoded network operating at 31.250 Kbps identical to Foundation Fieldbus H1, except that the protocol is specified by the Type 3 Data Link Layer and is identical to Profibus-DP. PA is used to communicate with process transmitters such as flow, pressure, temperature, and level. It supplies DC power to the transmitter.
Profibus-DP is also specified by IEC 61158 Type 3 but uses a TIA-485 physical layer and operates at speeds up to 12 Mbps over short line lengths. DP is optimized for communications between PLCs or between PLCs and their remote I/O units to carry registers of data from discrete sensors.
PA uses a PA/DP Coupler to bridge its data to a DP network to reach a controller.
So to summarize the significant difference between DP and PA is this:
PA provides power over the same two wires. DP requires separate power
DP is faster than PA
PA is intrinsically safe. DP is not
Although PROFIBUS PA is electrically identical to Foundation Fieldbus H1
there are many differences worth noting. These include:
. FF is time synchronized for better control
. FF is scheduled for better control
. FF separates non-real-time from real-time communication for better control
. FF has time-stamped alerts
. FF has automatic address assignment: plug-'n'-play
. FF includes a function block language for building control strategies
. FF has peer-to-peer communication for better control
. FF has firmware download
