LOG_GENERIC_OUTPUT Decoding and Providing Datasets for Transmission¶
Function Block LOG_GENERIC_OUTPUT
| Available as of PLC runtime system | V2.3 and above |
| Included in library | LogData_AC500_V23.lib |
| Type | Function Block with historical values |
This Function Block provides a decoded dataset of the corresponding data types from the SRAM-FIFOout of the Datalogger. The Function Block does not cover the transmission of the dataset. But it provides an interface for the user on which the data can be read and send according to application specific requirements and protocols.
The Function Block automatically reads the oldest dataset at a filling level of FIFOout > 0. Then the Function Block decodes the dataset from *.csv format and provids it to the outputs. The Function Block signals its availability through DONE = TRUE and STATE = zLOG_OUTPUT_DATA_AVAILABLE. If this dataset is processed by the user, the user will have to signal this by SENT = TRUE to the Function Block. By the edge 0/1 the RAM-FIFOout is decremented by the value 1, DONE changes to “FALSE” and on the output STATE the text “zLOG_OUTPUT_DATA_HAS_BEEN_SENT” appears. By a 1/0 edge on SENT the Function Block reads the next dataset (which is the same as the self triggered read without command, as long as SENT = false). This happens until FIFOOUT_LEVEL=0” and the Function Block signals “EMPTY”. At the same time at output STATE the message “zLOG_FIFOOUT_EMPTY” is given and all output values are deleted. While existing communication and exhausted FILE-FIFO the datasets, newly written by LOG_GENERIC_INPUT to the (in the %R area residing) FIFOin are continuously copied by the LOG_HANDLING directly to the (in the %M-area residing) FIFOout, as soon as there is space in the FIFOout for new datasets. For this the FIFOout should not be empty (EMPTY). It is different when FILE-FIFO is not empty. In this case at first FIFOout is fully decremented until FIFOOUT_LEVEL=0 and the Function Block signals “EMPTY”. After that a new dataset block is copied from FILE-FIFO into FIFOout. The capacity of the RAM-FIFOout per segment of the %M-area is at max ARRAY[0..160] OF ARRAY[0..399] OF BYTE. The ARRAY ocupies the complete segment 1 in the %M area of the CPU.
Note
A complete segment (segment 1 of the %R-area) is used for the SRAM-FIFOin (zLOG_CONST_FIFOLIMIT =160).
Functionality