Input Description

EN

Data_Type	Default_Value	Range	Unit
BOOL	FALSE	TRUE/FALSE	-

The input EN has to be driven in edge triggered mode.

The execution of the Function Block is started with a positive edge on the input EN.

In the first call it evaluates its inputs and creates a local copy of them. Afterwards it starts its internal algorithm. It may take several PLC task cycles until it is executed.

Once the execution is completed DONE and its other outputs are set. To start the Function Block again a new positive edge on the input EN has to be applied.

SLOT

Data_Type	Default_Value	Range	Unit
BYTE	0	0 … 4 (6)	-

At input SLOT, the Communication Module slot is specified which should be used by the Function Block.

The internal Communication Module always has the index 0. All external Communication Modules are serially numbered from right to left, starting with 1.

LEN (length)

Data_Type	Default_Value	Range	Unit
UINT	0	1 … 65535	byte

LEN tells the function block how large the buffer in SLV_STATE is. For each slave 4 bytes are needed.

SLV_DEVI (slave \ deviation)

Data_Type	Default_Value	Range	Unit
POINTER_TO_ARRAY_OF_DINT	0	-	-

The Input SLV_DEVI provides the address of an Arrary of DINT where the distributed clock deviation of each slave is written to.

Each Element of the array has the range -2147483647… 2147483647 in unit ns.

The required size of the array is calculated as number of configured ETHERCAT slaves multiplied with the size of DINT (4 bytes).

The size of the assigned array is provided at the Input LEN. If Input LEN is too small, an error will be returned.

If the value of LEN does not match with the assigned array, it can be overwritten. This will cause unexpected behavior.

Example

A system with a master and 5 slaves is configured.

ECAT_DCLK_DEVI_LEN := 20;

ECAT_DCLK_DEVI_SLV_DEVI: ARRAY [1..5] of DINT;