Details of the implicit exchange language objects for a Profibus DP function

At a Glance

The following tables present the language objects for Profibus DP communication. These objects are not integrated in the IODDTs.

List of the implicit exchange objects

The table below shows the implicit exchange objects.

Address	Type	Access	Meaning
%IWr.m.0.0 to %IWr.m.0.241	INT	R	242 DP input words.
%QWr.m.0.0 to %QWr.m.0.241	INT	R/W	242 DP output words.
%QWr.m.0.242	INT	-	%QW.r.m.0.242.0=0: Byte consistency %QW.r.m.0.242.0=1: Frame consistency
%QWr.m.0.243 to %QWr.m.0.253	INT	-	reserved.

The I/O exchange mode (%QWr.m.0.242) is available with PBY firmware V1.3IE14 or higher and requires the CPU 2.1OS version (or higher).

The application program can switch over between the following I/O exchange modes:

I/O Exchange Mode Byte Consistency (Recommended for Discrete I/O):

%QW.r.m.0.242.0=0 ==> Byte-by-byte data consistency within the Profibus frame, with high performance. No guarantee that all data of a Profibus frame will be consistency updated within on PLC cycle.
I/O Exchange Mode Frame Consistency (Recommended for Analog I/O):

%QW.r.m.0.242.0=1 ==> Data consistency over the total length of the Profibus frame, with reduced performance. In this mode the data of each Profibus frame is updated consistency within one PLC cycle.