RCOM_READΒΆ
| Parameter | Value |
|---|---|
| Library_File_Name | RCOM_AC500_V13.lib |
| Firmware | V1.3.1 |
| Type | Type_Function_Block_History |
| Group | RCOM/RCOM+ communication |
The Function Block reads data from an RCOM slave. For this, a READ job is sent to the communication partner via the CM574-RCOM communication module. As a result, the communication partner returns an acknowledgement including the data.
The data received from the slave are stored in a flag area specified at input DATA.
Data transmission (i.e. reading data) using the RCOM_READ Function Block is only possible, if the CM574-RCOM communication module has been initialized (RCOM Function Block) and if normalization has been performed previously.
Once a job is started (FALSE/TRUE edge at input EN), the data at the inputs NODE, ID, DATA and LEN must not be changed until the job is completed (i.e. until DONE = TRUE).
With each FALSE/TRUE edge at input EN the reading operation is performed once.
Further FALSE/TRUE edges at input EN are ignored until the reading operation is completed. The outputs DONE, ERR and ERNO are set when reading is completed.
Input NODE specifies the RCOM subscriber providing the data to be read. Input ID specifies the data record number within this subscriber and input LEN specifies the number of words to be transmitted.
If DONE = TRUE and ERR = FALSE, the reading operation could be completed successfully. If DONE = TRUE and ERR = TRUE, an error occurred and the error number is indicated at output ERNO. The outputs DONE, ERR and ERNO are reset with each falling edge at input EN.