9.2 PROFIBUS I/O channel blocks
The PROFIBUS I/O channels represent logical I/O points of the slave device. The PROFIBUS I/O channel
blocks fetch data from and write data to the PIOMB, based on whether the channel type is an input channel or
an output channel.
The following are the four PROFIBUS I/O channel blocks that can be assigned to the Control Module
containing the CEE to which the PIOMB is associated.
PbAiChannel - Represents an analog input point.
PbDiChannel - Represents a digital input point.
PbAoChannel - Represents an analog output point.
PbDoChannel - Represents a digital output point.
The PROFIBUS I/O channel blocks are located in the PGM_IF library in the Control Builder. A PROFIBUS
I/O channel block is assigned to a Control Module by dragging the appropriate channel block from the Library
view into the CM to which the CEE containing the PIOMB block is assigned.
For example, if the channel type of a PDC is Digital input (DI), you must drag-and-drop PBDICHANNEL from
the PGM_IF library into the Control Module containing the CEE.
The following figure displays a sample Control Module with PROFIBUS I/O channel blocks.
The execution period of the PROFIBUS I/O channel function blocks is dependent on the execution period of the
Control Module which contains the PROFIBUS I/O channel.
The PbAiChannel and PbDiChannel blocks fetch real-time data from the PIOMB for use in the control
9 PROFIBUS I/O MODULE (PIOMB) FUNCTION BLOCK