Siemens CP 343-1 manual Principle of Data Exchange over Profinet IO, B3L−21

6Configuring and Programming the CP as a PROFINET IO Device

6.2Principle of Data Exchange over PROFINET IO

Data Exchange between controller and CP as PROFINET IO device

Data exchange between a PROFINET IO controller and PROFINET IO device involves the following procedure:

SOn the PROFINET IO controller

Data exchange is initiated by the PROFINET IO controller that writes output data to the configured output area (O addresses) and fetches input data from the configured input area (I addresses).

SOn the PROFINET IO device

Data is processed by the CP in the PROFINET IO device on the interface to the PROFINET IO controller.

Communication within the PROFINET IO device involves calling the FCs PNIO_RECV and PNIO_SEND in the user program of the CPU.

	PROFINET IO device
	CPU	CP
	STEP 7	CP
	user program
		database
	PROFINET IO
Process	data areas (DB,
	bit memory)
outputs		Receive
	PNIO_RECV
	PNIO_SEND	Send
Process
inputs

PROFINET IO

Configured O addresses

Configured I addresses

PROFINET

IO controller

Figure 6-1 Interaction between PROFINET IO Device and PROFINET IO controller

Note

In the CPU of the device, the IO data areas for input data and output data are transferred as an entire area to or from one of the data areas (DB, bit memory) including any gaps.

CP 343-1 Lean for Industrial Ethernet / Manual Part B3L	B3L−21
Release 03/2007

C79000-G8976-C198-04