Overview

BufferMode

Some function blocks have a BufferMode input which is used to control the chronological order of movements. The buffer mode defines whether the function block works in non-buffered mode ("Aborting", standard behavior) or in buffered mode ("Buffered"). The difference between these two modes is the time when they begin their actions:

"Non-buffered Mode": The movement command is effective immediately, even if this interrupts another movement. The buffer of the commanded movements is deleted.
"Buffered Mode": The movement command waits until the current function block sets its output Done (or InPosition, or InVelocity, etc.). The buffer modes are also used to define how the velocity curve should look at the transition of the movements.

Table 38. The BufferMode input is an ENUM of type MC_BUFFER_MODE.

`Aborting`	Default mode without buffering. The function block starts immediately and aborts an active movement. The command takes immediate effect on the axis.
`Buffered`	The function block starts as soon as the last commanded movement is finished. No blending takes place here. The new movement starts at the velocity that the previous movement has when the end condition is reached (`Done`, `InVelocity`, `InEndVelocity`, `InGear`, `InSync`, `EndOfProfile`, etc.). If the previous movement was `MC_MoveAbsolute` or `MC_MoveRelative`, then the new movement starts at standstill.
`BlendingLow`	The function block starts as soon as the last commanded movement is finished. The axis does not stop between movements, but passes through the end position of the first movement at the lower velocity of the two movement commands.
`BlendingPrevious`	The function block starts as soon as the last commanded movement is finished. The axis does not stop between movements, but passes through the end position of the first movement at the velocity of the first movement command.
`BlendingNext`	The function block starts as soon as the last commanded movement is finished. The axis does not stop between movements, but passes through the end position of the first movement at the velocity of the second movement command.
`BlendingHigh`	The function block starts as soon as the last commanded movement is finished. The axis does not stop between movements, but passes through the end position of the first movement at the higher velocity of the two movement commands.

Supported Function Blocks

All function blocks that can be specified as buffered/blending commands have the following inputs and outputs:

BufferMode input (MC_BUFFER_MODE type)
Active output: (BOOL type)

A command is accepted when the function block switches to the state Busy after a new movement has been commanded.

Function Block	Can be Defined as a Buffered/Blending Command	Can be Followed by a Buffered/Blending Command	Relevant Signal for Activating the Next Buffered/Blending FB
`MC_Power`	No	No
`MC_Home`	No	No
`MC_Stop`	No	No
`MC_Halt`	No	No
`MC_MoveAbsolute` `MC_MoveRelative`	Yes	Yes	`Done`
`MC_MoveAdditive`	No	Yes (`Buffered` only)	`Done`
`MC_MoveSuperImposed` `MC_HaltSuperImposed`	No	No For more information, see: Behavior of MC_MoveSuperImposed and MC_HaltSuperImposed
`MC_MoveVelocity`	Yes	Yes (`Buffered` only)	`InVelocity`
`SMC_MoveContinuousAbsolute` `SMC_MoveContinuousRelative`	No	Yes (`Buffered` only)	`InEndVelocity`
`MC_PositionProfile` `MC_VelocityProfile` `MC_AccelerationProfile`	No	Yes (`Buffered` only)	`Done`
`MC_CamIn`	Yes (only `Buffered` and `BlendingPrevious`)	Yes, also if periodic (only `Buffered`)	`EndOfProfile`
`MC_CamOut`	No	Yes (`Buffered` only)	`Done`
`MC_GearIn`	Yes (`BlendingPrevious` only)	Yes (`Buffered` only)	`InGear`
`MC_GearOut`	No	Yes (`Buffered` only)	`Done`
`MC_GearInPos`	Yes (`BlendingPrevious` only)	Yes (`Buffered` only)	`InSync`
`SMC_FollowPosition` `SMC_FollowVelocity` `SMC_FollowPositionVelocity` `SMC_FollowSetValues`	No	No
`SMC_SetTorque`	No	No
`MC_Phasing`	No	No
`MC_Jog` `SMC_Inch`	No	No These function blocks should not be used when movements are commanded with buffer mode `Buffered` or `Blending*`. Jogging and the commanded movements could interrupt each other.
`SMC_BacklashCompensation`	No	No
`SMC_TrackAxis`	No	No
`SMC_TrackSetValues`	No	No

Note for MC_GearInPos and MC_GearIn: The behavior of other buffer modes as BlendingPrevious is difficult to establish. The main problem is that the velocity of these function blocks can change at any time depending on the master axis. Because blending works best when the blending speed is known as early as possible, only BlendingPrevious is supported.

In the case of BlendingPrevious, the direction of the master axis can also change at any time. This means that the direction that the slave axis should have for MC_GearInPos is known only when the blending is complete. However, we need a direction for the blending movement right when the blending begins. This is why the first movement defines both the blending velocity and the direction, regardless of the direction defined by the subsequent MC_GearIn(Pos).