Link Types and Link Values

Link Type and Link Value specify the condition that causes the motion controller to execute the next step in a sequence. These fields may be edited manually; however in most cases it is easier to use the Link Type and Link Value dialog box.

To use the Link Type and Link Value dialog box:

Select the Link Type or Link Value field on the axis you want to edit.
Press ENTER. You can also double-click on either of these fields.
Under Link Type Category, select the appropriate category. See the list below describing each category and the link types under each.
If you selected the Selected Axis (Enhanced) link type category, then select the axis you want to monitor.
Under Link Type, select the particular link type you want to use. See the list below and associated topics on each link type.
Under Link Condition, enter the settings for the particular link type selected.
The actual Link Type and Link Value that will be entered are displayed in the Link Type and Link Value dialog box to the left of the OK button. These values are updated as you make changes.
Click OK.

When viewed from a communication module (such as PROFIBUS-DP, Ethernet, etc.), the Link Type and Link Next fields are combined into a single 16-bit register, as detailed in the Link Type/Next topic. From PROFIBUS-DP Compact Mode and DI/O Command Mode, the Event Step Edit and Event Step Transfer commands are used to set this value. For all other communication types, they are accessed like any other register. Use the appropriate register map or use the Address Tool to find addresses of these values.

The Link Type and Link Value dialog box divides the link types into three categories:

System-wide (Basic, non-axis dependent)

These link types allow the axis to wait on a global condition such as a time delay or discrete input. These link types are listed below; select a link type for further details:

Link Type	Description
End of Sequence	This link type stops the event sequence.
Comm Trigger	Wait for synchronization signal from the communications master.
Delay	Wait for either a number of milliseconds or a number of counts on the edge or quadrature counter (if available).
Error Check	Wait for any of one or more errors on one or more axes.
Inputs, Multiple (Level only)	Wait for multiple discrete inputs.
Inputs, Single (Level/Edge)	Wait for a single discrete input edge or level.
Jump Using Inputs	Jump immediately to one of four event steps.
Loop	Define a loop in the step table.
Math Compares/Errors	This family of link types evaluate the results of one of the math commands (Add, Subtract, and MulDiv).
Multiple Axes In Position	Wait for several axes to be simultaneously in position.
Skew	Wait until the difference in actual positions or (following error) between axes exceeds a limit.
Timer	Start or check a timer.
Check Wait Bits	Check the Wait Bits.

Current Axis (Basic)

These link types allow the axis to wait for a condition based on its own state. These link types are listed below; select a link type for further details:

Link Type	Description
Absolute Limit Switch	Wait for the position to cross a specified value.
Pressure	Wait for the pressure (of either this axis, or the auxiliary pressure channel assigned to this axis) to cross a specified value.
Relative Limit Switch	Wait for the position to cross a position specified as a distance from either the start or end of the current move.
Speed	Wait for the speed to be above or below a specified value.
Status Bits	Wait for one or more status bits to be on or off.

Selected Axis (Enhanced)

These link types allow the axis to wait for conditions on another axis to occur before proceeding. These link types are listed below; select a link type for further details:

Link Type	Description
Position/Pressure	Wait for the position on an axis to be above or below a specified value.
Speed	Wait for the speed on an axis to be above or below a specified value.
Status Bits	Wait for one or more status bits on an axis to be on or off.