Twincat 3 Motion Control Utilities
The library is installed on the plc programming nodes as lcls-twincat-motion. Once installed, you can create a motion-ioc-compatible setup with default settings by declaring in Main:
M1: DUT_MotionStage;
fbMotion1: FB_MotionStage;
And invoking as:
fbMotion1(stMotionStage:=M1);
You would then link your hardware as appropriate to M1.Axis, M1.bLimitForwardEnable, M1.bLimitBackwardEnable, M1.bHome, M1.bBrakeRelease, and M1.bHardwareEnable.
Note that currently, the DUT_MotionStage instances must be named Main.M1, Main.M2... etc. due to limitations in the EPICS driver.
If you want to try out the IOC with a simulated axes, a shortcut function block is provided as:
fbMotionSim: FB_MotionStageSim;
fbMotionSim(stMotionStage:=M1);
This block removes all hardware-related protections to get the simulated axis moving, e.g.
stMotionStage.bLimitBackwardEnable := TRUE;
stMotionStage.bLimitForwardEnable := TRUE;
stMotionStage.bHardwareEnable := TRUE;
stMotionStage.bPowerSelf := TRUE;
stMotionStage.nEnableMode := ENUM_StageEnableMode.STAGE_ENABLE_ALWAYS;
fbMotionStage(stMotionStage := stMotionStage);
DUT_MotionStage has the following settings:
| Setting | Type | Usage |
|---|---|---|
bPowerSelf |
BOOL |
If TRUE (default), this function block will call MC_Power based on the bEnable attribute in the struct. Otherwise, you'll have to call MC_Power somewhere else (perhaps for MPS) |
nEnableMode |
ENUM_StageEnableMode |
Enable the NC Axis always, never, or only during motion (default). |
nBrakeMode |
ENUM_StageBrakeMode |
Disable the brake when the axis is enabled (default), or when it is in the standstill state. Note that this does nothing unless a brake is linked to bBrakeRelease. |
nHomingMode |
ENUM_EpicsHomeCmd |
Pick which switch to home to, or not to require homing (default) |
bGantryMode |
BOOL |
Set to TRUE to activate gantry EPS |
nGantryTol |
LINT |
If the gantry error is greater than this number of encoder counts, trigger a virtual limit. |
nEncRef |
ULINT |
Encoder count for gantry motion where the two axes are aligned. |
| Resource | Type | Usage |
|---|---|---|
DUT_MotionStage |
struct | Contains all relevant information about a single axis. You can pass this around and manipulate it inside of other function blocks. It relys on FB_MotionStage to provide the logic. |
FB_MotionStage |
function block | Provides a connection to ESS's motion library for motor record functionality, as well as some standard handling of brake and auto enable/disable. |
ENUM_EpicsHomeCmd |
enum | Options for axis homing through the motor record |
ENUM_EpicsMotorCmd |
enum | Options for axis commands through the motor record. You can use these through TwinCAT too. |
ENUM_StageBrakeMode |
enum | Options for axis brake mode. Brake can be enabled at standstill or at disabled. |
Enum_StageEnableMode |
enum | Options for axis enable/disable handling. Axis can be enabled always, never, or only during motion. |
DUT_PositionState |
struct | Contains all information about a specific position state, e.g. "out" |
FB_StatePTPMove |
function block | Moves an axis to a specific position state. |