General functioning of the FB_CTRL_... Function blocks stParams: The necessary parameters are passed to the function block with this structure. The variables tTaskCycleTime and tCtrlCycleTime are contained in all the parameter structures. These parameters function in the following way: The parameter tTaskCycleTime specifies the cycle time with which the function block is called. If the block is called in every cycle this corresponds to the cycle time of the calling task. If it is only called in every second cycle, the time must correspondingly be doubled. The parameter tCtrlCycleTime indicates the control loop's sampling time.
This time must be greater than or equal to the parameter tTaskCycleTime. If the sampling time is set equal to tTaskCycleTime then the block is executed with every call. If a factor of 5 greater is selected, the block is only processed in every 5th call. This makes it possible to implement slow control loops even in a fast task. The parameters tTaskCycleTime and tCtrlCycleTime are of type TIME and therefore do not permit inputs of less than 1ms. To use the controller in a fast PLC task with a cycle time of less than 1ms, a global base time can be specified as reference for the specified cycle times. Notes on using the base time. [ } 12] Examples :
It is assumed that the block is called in every task cycle. The outputs of the function blocks eState: This output indicates the current internal state of the block. bError: An error in the block is indicated by an TRUE at this boolean output. TS4100 11 Version: 1.1 eCTRL MODE MANUAL _ _ The value of the input value fManSyncValue is provided at the output (manual operation). Task Configu- ration Parameter: tTaskCycleTime Parameter: tC- trlCycleTime Method of operation: T#10ms T#10ms T#10ms The control loop is processed using a 10 ms sampling time. T#10ms T#10ms T#50ms The control loop is processed using a 50 ms sampling time.
T#100ms T#100ms T#100ms The control loop is processed using a 100 ms sampling time. T#100ms T#100ms T#50ms ERROR, execution not possible! T#100ms T#50ms T#50ms ERROR, although the block has been executed, incorrect output values have been calculated! eCTRL STATE IDLE _ _ The block has successfully been reset, and is now waiting for selection of the operating mode. eCTRL STATE PASSIVE _ _ The block is in the passive state in which no calculations are carried out. eCTRL STATE ACTIVE _ _ The block is in the active state, which is the normal operating state. eCTRL STATE RESET _ _ A reset request is being processed, but the reset has not yet been completed.
eCTRL STATE MANAUL _ _ The block is in the manual state, and the output can be manually specified at the appropriate input. eCTRL STATE ... _ _ If there are any other internal states, they are described together with the corresponding blocks. eCTRL STATE ERROR _ _ An error has occurred; the block is not executed when in this state. See eErrorId for further information.