Data Area tab

In general, TcCOM objects can contain data areas that can be used by the environment (e.g., by a PLC instance or by the TwinCAT I/O area). For TwinCAT MC3 TcCOM objects, you have a choice of data structures to use via the Data Area tab.

Notice

Unlinked CDTs can cause a floating-point exception when accessed

Comparisons with NaN values can lead to an exception, which results in the runtime stopping and potentially causing machine damage.
Valid data can only be expected if IsConnected = TRUE. Otherwise, there is a risk of an inconsistent or invalid data set, which may lead to unpredictable consequences and unexpected behavior. Arithmetic operations using invalid values can cause floating-point exceptions in the processor's floating-point unit.

Switch off the Floating Point Exceptions if NaN values are to be used and processed in the application.
Before accessing a CDT (e.g., from the PLC), check the CDT's IsConnected.
Familiarize yourself with how to handle named constants and NaN values.

PlcToMc (Input)

Enable (default)	Name	Type	Description
	Std	POINTER TO MC.CDT_PLCTOMC_AXIS_STD	Standard cyclic data structure for enabling the axis and setting the velocity override.

McToPlc (Output)

Name	Type	Description
Std	POINTER TO MC.CDT_MCTOPLC_AXIS_STD	Standard cyclic data structure containing the axis Oid and key status information.
Set	POINTER TO MC.CDT_MCTOPLC_AXIS_SET	Optional cyclic data structure containing information about the axis's current setpoints. Notice Valid data can only be expected if IsConnected = TRUE. Valid data must be validated in accordance with the following chapter: Constants (Named Constants)
Act	POINTER TO MC.CDT_MCTOPLC_AXIS_ACT	Optional cyclic data structure containing information about the axis's current actual values. Notice Valid data can only be expected if IsConnected = TRUE. Valid data must be validated in accordance with the following chapter: Constants (Named Constants)
Modulo	POINTER TO MC.CDT_MCTOPLC_AXIS_MODULO	Optional cyclic data structure containing information about the axis's module position. To calculate the module position accurately, set the Is Modulo Axis parameter to TRUE in the Axis Parameters (Init) section, and configure the Position Modulus and Position Modulo Tolerance Window parameters accordingly. Notice Valid data can only be expected if IsConnected = TRUE. Valid data must be validated in accordance with the following chapter: Constants (Named Constants)
LoadControl	POINTER TO MC.CDT_MCTOPLC_AXIS_LOADCONTROL	Optional cyclic data structure. Notice Valid data can only be expected if IsConnected = TRUE. Valid data must be validated in accordance with the following chapter: Constants (Named Constants)
Fluidpower	POINTER TO MC.CDT_MCTOPLC_AXIS_FLUIDPOWER	Optional cyclic data structure. Notice Valid data can only be expected if IsConnected = TRUE. Valid data must be validated in accordance with the following chapter: Constants (Named Constants)