Optimizing SimpleMotion V2 performance - Revision history

Tero K at 15:57, 9 February 2017

2017-02-09T15:57:31Z

2017-02-09T15:50:47Z

2015-06-10T11:55:50Z

‎Writing and reading multiple values at one cycle

2015-06-10T11:54:44Z

‎Writing and reading multiple values at one cycle

2014-03-26T14:01:04Z

2014-01-08T13:22:06Z

‎Writing multiple and reading single value at one cycle

2014-01-08T13:18:17Z

2014-01-08T00:40:15Z

‎Queued calls

2014-01-08T00:38:08Z

‎Writing multiple and reading single value at one cycle

2014-01-08T00:33:35Z

‎Writing multiple and reading single value at one cycle

@@ Line 269: / Line 269: @@
      //TODO add some SM error checking in appropriate places
 </syntaxhighlight>
+==See also==
 [[Category:Development]]
 [[Category:SimpleMotion]]

@@ Line 269: / Line 269: @@
      //TODO add some SM error checking in appropriate places
 </syntaxhighlight>
 [[Category:Development]]
 [[Category:SimpleMotion]]

@@ Line 185: / Line 185: @@
      smGetQueuedSMCommandReturnValue( busHandle,&readout3 );
 ====Writing multiple and reading single value at one cycle====
 If we need to read only one variable, we don't need to change readout parameter address during cycle and further improve performance. In this case we set it at initialization and then all consequent commands will return the desired return value.

@@ Line 140: / Line 140: @@
      //TODO add some SM error checking in appropriate places
 </syntaxhighlight>
 ====Writing multiple and reading single value at one cycle====

@@ Line 206: / Line 206: @@
      //write the parameter value to previously set parameter address. SMPCMD_32B consumes 4 bytes of outbound payload
      smAppendSMCommandToQueue( busHandle, SMPCMD_32B, paramValue3);
      //execute commands over SM bus
      smExecuteCommandQueue( busHandle, deviceAddress );
-    //notice that we don't need to change readout parameter addresses here as it we have only one variable to read out
+     /*read value commands (one per each append command before execute). Size of inbound payload depends on
+     what was set to SMP_RETURN_PARAM_LEN at initialization. In this case 3 bytes per return value (total 6x3). */
      /*read value commands (one per each append command). Size of inbound payload depends on
      what was set to SMP_RETURN_PARAM_LEN at initialization */
      smGetQueuedSMCommandReturnValue( busHandle,&nul );
      smGetQueuedSMCommandReturnValue( busHandle,&nul );

@@ Line 44: / Line 44: @@
 smGetQueuedSetParamReturnValue(  busHandle, &nul );
 smGetQueuedSetParamReturnValue(  busHandle, &nul );
 </syntaxhighlight>
@@ Line 135: / Line 137: @@
      smGetQueuedSMCommandReturnValue( busHandle,&readout2 );
      smGetQueuedSMCommandReturnValue( busHandle,&readout3 );
 </syntaxhighlight>
@@ Line 166: / Line 170: @@
      smGetQueuedSMCommandReturnValue( busHandle, &nul );
      smGetQueuedSMCommandReturnValue( busHandle, &nul );
 </syntaxhighlight>
@@ Line 214: / Line 220: @@
      smGetQueuedSMCommandReturnValue( busHandle,&nul );
      smGetQueuedSMCommandReturnValue( busHandle,&readout1 ); //we could get the readout1 from any of the above lines as well
 </syntaxhighlight>
 [[Category:Development]]

@@ Line 46: / Line 46: @@
 </syntaxhighlight>
-In the above example, the ''smExecuteCommandQueue'' is the only line where RS485 is being used thus generating only one write-read latency. ''smAppendSetParamCommandToQueue'' and ''smGetQueuedSetParamReturnValue'' transfer data only inside SMV2 library buffers and are fast calls.
+In the above example, the ''smExecuteCommandQueue'' is the only line where RS485 is being used thus generating only one write-read latency instead. ''smAppendSetParamCommandToQueue'' and ''smGetQueuedSetParamReturnValue'' transfer data only inside SMV2 library buffers and are fast calls. The optimized code does only one bus transfer cycle instead of four.
 ====Queued size limit====

@@ Line 143: / Line 143: @@
 <syntaxhighlight lang="c">
      /* Variables:
-     -readOutParamAddr1 will define the parameter numbers to read out into readout1
+     -readOutParamAddr1 will define the parameter number to be read out into readout1
      */
      smint32 nul, readOutParamAddr1=SMP_ACTUAL_POSITION_FB;