Input DescriptionΒΆ
EN (enable)
Data type: BOOL
If a FALSE to TRUE edge is applied to input EN, all further inputs are read in.
If the input values are valid, a corresponding request message is sent to the Communication Module. While this request message is processed, output DONE is set to FALSE.
If at least one input value is invalid, an error is indicated at output ERR. Additionally, the termination of the request processing is indicated by DONE = TRUE. While the request is processed, state changes at input EN are recognized but not evaluated.
SLOT (slot)
Data type: BYTE
At input SLOT the Communication Module slot (module number) is selected which should be used by the Function Block.
The internal Communication Module SLOT always has the module number 0. All external Communication Modules are serially numbered from right to left, starting with module number 1.
SLV (slave)
Data type: BYTE
At input SLV the bus address of the DP slave is applied, the data of which shall be read.
Different value ranges have to be considered depending on the used Communication Module:
- CM572-DP:0..126
- CM592-DP:0..125
SLV_SLOT
Data type: BYTE
At input SLV_SLOT the number of the slot within the slave is specified, the data of which shall be read.
Valid values: 0..254.
SLV_IDX
Data type: BYTE
At input SLV_IDX the number of the index within the slot is specified, the data of which shall be read.
Valid values: 0..254.
LEN (length)
Data type: BYTE
The length of the data block to be read is specified at input LEN.
Valid values: 0..240.
Note
Function Block reads a complete data block independent of input LEN.
If length of data block is unknown, set LEN = 240 (max. data LEN).
Caution
:strong:Overwriting of variables to data!
If LEN is lower than length of data block the following variables to data will be overwritten!
DATA (data)
Data type: DWORD
At input DATA the address of the variable where the received data block shall be stored is specified via the ADR address operator.
The size of the variable must be big enough to store the complete data block (e.g. BYTE array). Furthermore, the format (BYTE, WORD, etc.) of the data must be considered.