PLC Library: NCI Interpreter

The TwinCAT library TcNci.lib contains function blocks for operation of the NC interpreter from the PLC.

The following function blocks are contained in the TcNci.lib library.

Function block	Description
ItpConfirmHsk	Acknowledges an M-function of type handshake
ItpDelDtgEx	Triggers “Delete Distance to go” in the NC
ItpEnableDefaultGCode	Executes a user-defined standard G-Code before the start of each NC program
ItpEStopEx	Triggers the NCI EStop
ItpGetBlockNumber	Provides the block number of the NC program for the cyclic interface
ItpGetBottleNeckLookAheadEx	Provides the value of the look-ahead for bottleneck detection
ItpGetBottleNeckModeEx	Provides the response mode for bottleneck detection
ItpGetChannelId	Provides the channel ID
ItpGetChannelType	Provides the channel type of the cyclic interface
ItpGetCyclicLRealOffsets	Provides the index offset of the LREAL variables used in the cyclic channel interface
ItpGetCyclicUdintOffsets	Provides the index offset of the UDINT variables used in the cyclic channel interface
ItpGetError	Provides the error number
ItpGetGroupAxisIds	Provides the axis IDs that were configured for the group
ItpGetGroupId	Provides the group ID
ItpGetHParam	Provides the current H-parameter from the NC
ItpGetHskMFunc	Provides the current M-function number of type handshake
ItpGetItfVersion	Provides the current version of the cyclic interface
ItpGetOverridePercent	Provides the channel override in percent
ItpGetSParam	Provides the current S-parameter from the NC
ItpGetStateInterpreter	Provides the current interpreter state
ItpGetTParam	Provides the current T-parameter from the NC
ItpGetVersion	Provides the version number of this library
ItpGoAheadEx	Triggers the GoAhead function (decoder stop with external trigger event)
ItpHasError	Determines whether an error is present
ItpIsFastMFunc	Determines whether the M-function number provided is present in the form of a fast M-function
ItpIsEStopEx	Determines whether an EStop is executed or pending
ItpIsHskMFunc	Determines whether an M-function of type handshake is present
ItpLoadProgEx	Loads an NC program using program names
ItpReadCyclicLRealParam1	Reads the first LReal parameter from the cyclic channel interface
ItpReadCyclicUdintParam1	Reads the first UDINT parameter from the cyclic channel interface
ItpReadRParamsEx	Reads arithmetic parameters
ItpReadToolDescEx	Reads the tool description from the NC
ItpReadZeroShiftEx	Reads the zero offset shift from the NC
ItpResetEx2	Carries out a reset of the interpreter or of the NC channel
ItpResetFastMFuncEx	Resets a fast signal bit
ItpSetBottleNeckLookAheadEx	Sets the value of the look-ahead for bottleneck detection
ItpSetBottleNeckModeEx	Sets the response mode when bottleneck detection is switched on
ItpSetCyclicLRealOffsets	Sets the index offsets of the LREAL variables used in the cyclic channel interface
ItpSetCyclicUdintOffsets	Sets the index offsets of the UDINT variables used in the cyclic channel interface
ItpSetOverridePercent	Sets the channel override in percent
ItpSetSubroutinePathEx	Optionally sets the search path for subroutines
ItpSetToolDescNullEx	Sets all tool parameters (including number and type) to zero
ItpSetZeroShiftNullEx	Set all zero offset shifts to null
ItpSingleBlock	Enables or disables the single block mode in the NCI.
ItpStartStopEx	Starts or stops the interpreter (NC channel)
ItpStepOnAfterEStopEx	Enables further processing of the parts program after an NCI EStop
ItpWriteRParamsEx	Writes arithmetic parameters
ItpWriteToolDescEx	Writes the tool description into the NC
ItpWriteZeroShiftEx	Writes the zero offset shift into the NC
Block search (for description of the functionality see Blocksearch)
ItpBlocksearch	Sets the interpreter to a user-defined location, so that NC program execution continues from this point.
ItpGetBlocksearchData	Reads the current state after an NC program interruption.
ItpStepOnAfterBlocksearch	Starts the motion after a block search.
Retrace
ItpEnableFeederBackup	Enables the backup list for retracing
ItpIsFeederBackupEnabled	Reads whether the backup list for retracing is active
ItpIsFirstSegmentReached	Reads whether the start position is reached during retracing
ItpIsFeedFromBackupList	Reads whether feeder entries were sent from the backup list
ItpIsMovingBackwards	Reads whether backward movement occurs on the current path
ItpRetraceMoveBackward	Performs a backward movement on the path
ItpRetraceMoveForward	Performs a forward movement on the path. This is called to cancel retracing.

Requirements

The library to be integrated depends on the TwinCAT version. From TwinCAT version 2.8 TcNci.lib should be used. For older versions TcNciItp.lib should be used. The interface for the function blocks etc. of both libraries is the same.

Development environment	Target platform	PLC libraries to include
TwinCAT v2.7.0	PC (i386)	TcNciItp.lib
from TwinCAT v2.8.0	PC (i386)	TcNci.lib

Function blocks for compatibility with existing programs:

	Function blocks for compatibility The purpose of the function blocks listed is to ensure compatibility with existing projects. It is not advisable to use these function blocks for new projects. Instead, the equivalent function blocks shown in the table above should be used.

Function block	Description
ItpDelDtg	Triggers “Delete Distance to go” in the NC
ItpEStop	Triggers the NCI EStop
ItpGetBottleNeckLookAhead	Provides the value of the look-ahead for bottleneck detection
ItpGetBottleNeckMode	Provides the response mode for bottleneck detection
ItpGoAhead	Triggers the GoAhead function
ItpIsEStop	Determines whether an EStop is executed or pending
ItpLoadProg	Loads an NC program using program names
ItpReadRParams	Reads arithmetic parameters
ItpReadToolDesc	Reads the tool description from the NC
ItpReadZeroShift	Reads the zero offset shift from the NC
ItpReset	Carries out a reset of the interpreter or of the NC channel
ItpResetEx	Carries out a reset of the interpreter or of the NC channel.
ItpResetFastMFunc	Resets a fast signal bit
ItpSetBottleNeckLookAhead	Sets the value of the look-ahead for bottleneck detection
ItpSetBottleNeckMode	Sets the response mode when bottleneck detection is switched on
ItpSetSubroutinePath	Optionally sets the search path for subroutines
ItpSetToolDescNull	Sets all tool parameters (including number and type) to zero
ItpSetZeroShiftNull	Sets all origins to zero
ItpStartStop	Starts or stops the interpreter (NC channel)
ItpStepOnAfterEStop	Enables further processing of the parts program after an NCI EStop
ItpWriteRParams	Writes arithmetic parameters
ItpWriteToolDesc	Writes the tool description into the NC
ItpWriteZeroShift	Writes the zero offset shift into the NC

Further Information