ecmc_master_slave

Standard syncronization scripts for ecmc. The module provides:

• Syncronization scripts
• Generic state machine

Syncronization scripts

Syncronazation can be done both by defining the forward adn inverse kinematcis as equations or by matrices.

The module implement 5 generic syncronazation scripts based on the matrix approach:

• axis_kin_2DoF.plc_inc : Kinematics for a 2 Dof system (slits)
• axis_kin_3DoF.plc_inc : Kinematics for a 3 Dof system (slits)
• axis_kin_4DoF.plc_inc : Kinematics for a 4 Dof system (slits)
• axis_kin_5DoF.plc_inc : Kinematics for a 5 Dof system (slits)
• axis_kin_6DoF.plc_inc : Kinematics for a 6 Dof system (slits) and 2 dedicated:
• axis_kin_slit.plc_inc : Dedicated script for a slit system based on equations (including interlocks and softlimits)
• axis_kin_mirror.plc_inc : Dedicated script for a 5 DoF mirror based on matrices

Generic scripts (axis_kin_xDoF.plc_inc)

The generic scripts needs a few macros:

• AX_S<index> : Axis index for slave axes 1..DoF
• AX_M<index> : Axis index for master axes 1..DoF
• FWD<index\ : Forward kinematics array 1..DoF
• INV<index\ : Inverse kinematics array 1..DoF

State machine

The state machine makes sure that master and slaved axes cannot run simultaneous. However, several master axes or several slave axes can run at the same time. The state machine is implemented in the file axis_sm.plc.inc in this module.

The state machine needs two macros:

• GRP_ID_MA : Group id for master axes (most often virtual axes)
• GRP_ID_SA : Group id for slave axes (most often real axes)

The easiest way to create a group is to just add it in the axis yaml configuration:

axis:
  id: 5
  group: realAxes

If the group does not exist, it will be created. The id of the group will be accessible through the environment variable "GRP_<group_name>_ID", in this case "GRP_realAxes_ID". This macro can the be used when loading the PLC-code.

Using the scripts

The easiest way is to generate a main plc file and then use include to access the kinematic and state machine scripts.

Example for a slit system:

/* Forward kinematics to calculate virtual axes from real axes
   | CEN    |  = FWD *   | S1_LO |
   | GAP    |            | S2_HI |
   
   Equations:
     ax{AX_CEN}.enc.actpos:=(ax{AX_LO}.enc.actpos+ax{AX_HI}.enc.actpos)/2;
     ax{AX_GAP}.enc.actpos:=ax{AX_HI}.enc.actpos-ax{AX_LO}.enc.actpos;
*/
var FWD1[2] := {0.5, 0.5};
var FWD2[2] := { -1,  1 };

/* Inverse kinematics to calculate real axes from virtal axes
   | S1_LO    |  = INV *   | CEN |
   | S2_HI    |            | GAP |

   Equations:
     ax{AX_LO}.traj.extsetpos:=ax{AX_CEN}.traj.setpos-ax{AX_GAP}.traj.setpos/2;
     ax{AX_HI}.traj.extsetpos:=ax{AX_CEN}.traj.setpos+ax{AX_GAP}.traj.setpos/2;
*/
var INV1[2] := {  1,   -0.5};
var INV2[2] := {  1,    0.5};

# Kinematics for slit system. 
include "axis_kin_2DoF.plc_inc"

# State machine
include "axis_sm.plc_inc"

The main plc file can then be loaded into ecmc with appropriate macros (also not the INC):

${SCRIPTEXEC} ${ecmccfg_DIR}loadPLCFile.cmd,    "FILE=./cfg/axis_main.plc, PLC_ID=1, INC=.:${ecmc_master_slave_DIR}, PLC_MACROS='PLC_ID=1, AX_M1=12, AX_M2=13, AX_S1=5, AX_S2=6, GRP_ID_SA=${GRP_realAxes_ID}, GRP_ID_MA=${GRP_virtualAxes_ID}'"

NOTE: Macros cannot not be used in the include statement. The path to this module needs to set in the INC parameter to loadPLCFile.cmd

Examples

See examples dir for usage:

• slits (equations, 2DoFs matrix)
• mirror (matrix)