Input Description

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 output data of which shall be read.

DATA (data)

Data type: DWORD

At input DATA the address of the variable to be used to store the received output data is specified via the address operator ADR.

The size of this variable must be big enough to store all output data of the slave (e.g. BYTE array). Furthermore, the format (BYTE, WORD, etc.) of the slave outputs must be considered.

If the slave has mixed outputs of different types, it is recommended to first define a STRUCT data type which represents an image of the slave’s output structure (see I/O configuration of the slave) and then to declare a variable of this type.