Sample program 3 (write LookUp table)

Download TwinCAT 3 project: program link

Program description

Transmission of LookUp table interpolation values for mapping of an equation f(x) = x³via CoE into the terminal.

PROGRAM MAIN

VAR

   //LookUp-Table (LUT) generated by: MBE * x³

   aLUT:ARRAY[0..99] OF DINT :=

      -7812500,-7812500,-7493593,-6894382,

      -7174765,-6051169,-6855859,-5279674,-6536953,-4576709,

      -6218125,-3939087,-5899218,-3363620,-5580390,-2847120,

      -5261484,-2386402,-4942578,-1978275,-4623750,-1619555,

      -4304843,-1307052,-3985937,-1037580,-3667109,-807951,

      -3348203,-614978,-3029375,-455472,-2710468,-326248,

      -2391562,-224117,-2072734,-145892,-1753828,-88385,

      -1434921,-48409,-1116093,-22776,-797187,-8300,

      -478281,-1792,-159453,-66,159453,66,

      478281,1792,797187,8300,1116093,22776,

      1434921,48409,1753828,88385,2072734,145892,

      2391562,224117,2710468,326248,3029375,455472,

      3348203,614978,3667109,807951,3985937,1037580,

      4304843,1307052,4623750,1619555,4942578,1978275,

      5261484,2386402,5580390,2847120,5899218,3363620,

      6218125,3939087,6536953,4576709,6855859,5279674,

      7174765,6051169,7493593,6894382,7812500,7812500

];

   // For CoE 0x8000 and 0x8005 - write values:

   // ===============================================

   wCoEIndexScaler :WORD := 16#8005; // CoE Index

   wState          :BYTE := 0; // Write status

   fb_coe_writeEx  :FB_EcCoESdoWriteEx; // Function Block for writing in CoE

   userNetId       :T_AmsNetId := '172.128.1.1.5.1'; // Have to be entered

   userSlaveAddr   :UINT := 1003; // Have to be entered

   bWriteLUT2CoE   :BOOL:=FALSE; // Sign for start writing

   bError          :BOOL:=FALSE; // Sign for any error

END_VAR

The variable "startWrite" (BOOL) is also declared in sample program 4.
The variable 'userNetId' must include the EtherCAT net ID of the device. It can be viewed in the "EtherCAT" tab under "Device (EtherCAT)".
The variable "userSlaveAddr" must contain the EtherCAT address of the terminal.

// Example program 3:

// ###### Write LookUp table into CoE object 0x8005: #######

IF bWriteLUT2CoE THEN

CASE wState OF

0:

      fb_coe_writeEx(bExecute := FALSE);// Prepare CoE-Access

      wState := wState + 1;// Next state

1:

      // Write 100 X/Y LookUp-Table entries

      fb_coe_writeEx(

         sNetId:= userNetId,

         nSlaveAddr:= userSlaveAddr,

         nSubIndex:= 1,

         nIndex:= wCoEIndexScaler,

         pSrcBuf:= ADR(aLUT),

         cbBufLen:= SIZEOF(aLUT),

         bCompleteAccess:= TRUE,

         bExecute:= TRUE

);

      wState := wState + 1; // Next state

2:

      // Proceed with writing to CoE

      fb_coe_writeEx();

      IF NOT fb_coe_writeEx.bBusy THEN

         wState := 0;// Done

         bWriteLUT2CoE := FALSE;

         bError := fb_coe_writeEx.bError; // See nErrId if TRUE

      END_IF

END_CASE

END_IF

A simple variable query, e.g., via button linked with bEnable, can be used to initiate the transfer. The variable declaration must contain

VAR_INPUT

   bEnable   AT%I*   :BOOL;

END_VAR

and the following program lines:

IF bEnable AND NOT startWrite THEN

   bWriteLUT2CoE := TRUE;

END_IF