MC_CamIn, MCP_CamIn – Engage the cam

Block SymbolsLicensing group: MOTION CONTROL

Function Description

The MC_CamIn and MCP_CamIn blocks offer the same functionality, the only difference is that some of the inputs are available as parameters in the MCP_ version of the block.

The MC_CamIn block switches on a mode in which the slave axis is commanded to position which corresponds to the position of master axis transformed with with a function defined by the MCP_CamTableSelect block (connected to CamTableID input). Denoting the transformation as $C a m (x)$ , master axis position $P o s M$ and slave axis position $P o s S$ , we obtain (for absolute relationship, without phasing): $P o s S = C a m ((P o s M - M a s t e r O f f s e t) ∕ M a s t e r S c a l i n g) * S l a v e S c a l i n g + S l a v e O f f s e t$ . This form of synchronized motion of the slave axis is called electronic cam.

The cam mode is switched off by executing other motion block on slave axis with mode aborting or by executing a MC_CamOut block. The cam mode is also finished when the master axis leaves a non-periodic cam profile. This situation is indicated by the EndOfProfile output.

In case of a difference between real position and/or velocity of slave axis and cam-profile slave axis position and velocity, some transient trajectory must be generated to cancel this offset. This mode is called ramp-in. The ramp-in function is added to the cam profile to eliminate the difference in start position. The RampIn parametr is an average velocity of the ramp-in function. Ramp-in path is not generated for RampIn=0 and error -707 (position or velocity step) is invoked if some difference is detected. Recommended value for the RampIn parametr is 0.1 to 0.5 of maximal slave axis velocity. The parameter has to be lowered if maximal velocity or acceleration error is detected.

Inputs

uMaster	Master axis reference	Reference
uSlave	Slave axis reference	Reference
CamTableID	Cam table reference (connect to MCP_CamTableSelect.CamTableID)	Reference
Execute	The block is activated on rising edge	Bool
MasterOffset	Offset in cam table on master side [unit]	Double (F64)
SlaveOffset	Offset in cam table on slave side [unit]	Double (F64)
MasterScaling	Overall scaling factor in cam table on master side	Double (F64)
SlaveScaling	Overall scaling factor in cam table on slave side	Double (F64)
StartMode	Select relative or absolute cam table	Long (I32)
	1 .... Master relative 2 .... Slave relative 3 .... Both relative 4 .... Both absolute
BufferMode	Buffering mode	Long (I32)
	1 .... Aborting (start immediately) 2 .... Buffered (start after finish of previous motion) 3 .... Blending low (start after finishing the previous motion, previous motion finishes with the lowest velocity of both commands) 4 .... Blending high (start after finishing the previous motion, previous motion finishes with the lowest velocity of both commands) 5 .... Blending previous (start after finishing the previous motion, previous motion finishes with its final velocity) 6 .... Blending next (start after finishing the previous motion, previous motion finishes with the starting velocity of the next block)
RampIn	RampIn factor (0 = RampIn mode not used); average additive velocity (absolute value) during ramp-in process	Double (F64)

Outputs

yMaster	Master axis reference	Reference
ySlave	Slave axis reference	Reference
InSync	Slave axis reached the cam profile	Bool
CommandAborted	Algorithm was aborted	Bool
Busy	Algorithm not finished yet	Bool
Active	The block is controlling the axis	Bool
Error	Error occurred	Bool
ErrorID	Result of the last operation	Error
	i .... REXYGEN general error
EndOfProfile	Indicate end of cam profile ( not periodic cam only)	Bool
SyncDistance	Position deviation of the slave axis from synchronized position	Double (F64)

Example

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