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Profibus Library

The Profibus"Process Field Bus" Profibus is the most popular type of fieldbus (see Fieldbus entry in the glossary) used worldwide driver has a thread that performs the exchange with the HW from time to time. The minimal exchange period (as well as the thread system priority) can be configured.

Name	Description
PBGetExchPrio PBSetExchPrio	Return or change the priority of the I/O exchange thread. Which can be: #define CIF_EXCHANGE_PRIORITY_NORMAL 0 /* Profibus exchange thread priority lower than VM thread priority / #define CIF_EXCHANGE_PRIORITY_HIGHER 1* /* Profibus exchange thread priority equal to VM thread priority */
PBGetExchPeriod PBSetExchPeriod	Return or change the minimum period of the I/O exchange thread with the HW (in PLC"Programmable Logic Controller" A Programmable Logic Controller, PLC, or Programmable Controller is a digital computer used for automation of industrial processes, such as control of machinery on factory assembly lines. Used to synchronize the flow of inputs from (physical) sensors and events with the flow of outputs to actuators and events cycles). 2 is the minimum value. Taking the system load into account, it can be set to more than 2. Example: set the period to 2 if you want the exchange to be performed at the most once every 2 cycles (compared with the VM cycle)
PBGetExchNb	Return the amount of exchange performed with the HW
PBGetLastPeriod	Return the last period between two exchanges
PBGetMaxPeriod	idem but max period
PBResetStats	ResetNew start of the microprocessor the previous statistics of the I/O exchange thread. Which are: the number of exchanges done the last exchange period the maximum exchange period Statistics are reset each time the driver is Open (i.e. when the program start)

Table 11-51: List of Profibus FB