NI-DAQ Cards on Linux - Revision history

JamesYeung: /* How to Read Encoder Counts */

2010-06-15T19:27:07Z

How to Read Encoder Counts

JamesYeung: /* Example Code */

2010-06-15T19:26:06Z

Example Code

JamesYeung: /* Timing Data */

2010-06-15T19:23:11Z

Timing Data

Lynch: /* Overview */

2010-06-12T18:53:24Z

Overview

JamesYeung: /* How to Write Digital Outputs */

2010-06-12T01:34:04Z

How to Write Digital Outputs

JamesYeung: /* Digital */

2010-06-12T01:31:09Z

Digital

JamesYeung: /* Timing Data */

2010-06-12T01:30:50Z

Timing Data

JamesYeung: /* Timing Data */

2010-06-12T01:29:07Z

Timing Data

JamesYeung at 01:28, 12 June 2010

2010-06-12T01:28:37Z

JamesYeung: /* Overview */

2010-06-12T01:25:17Z

Overview

@@ Line 337: / Line 337: @@
 ===How to Read Encoder Counts===
-See page 136-137 of the manual for NI PCI-6220 for the pins for ChA and ChB.
+See page 136-137 of the [http://hades.mech.northwestern.edu/images/8/87/Nipci-6220_manual.pdf NIPCI-6220 Manual] for the ChA and ChB pins.
 <pre>
 #include <stdio.h>

@@ Line 316: / Line 316: @@
 		DAQmxErrChk(DAQmxWriteDigitalLines(taskHandle,1,TRUE,10.0,DAQmx_Val_GroupByScanNumber,&data,&written,NULL));
 		printf("%4d\t%d\n", ii, data);
+	}
+Error:
+	if( DAQmxFailed(error) )
+		DAQmxGetExtendedErrorInfo(errBuff,2048);
+	if( taskHandle!=0 )  {
+		/*********************************************/
+		// DAQmx Stop Code
+		/*********************************************/
+		DAQmxStopTask(taskHandle);
+		DAQmxClearTask(taskHandle);
+	}
+	if( DAQmxFailed(error) )
+		printf("DAQmx Error: %s\n",errBuff);
+	printf("End of program, press Enter key to quit\n");
+	getchar();
+	return 0;
+}
+</pre>
+===How to Read Encoder Counts===
+See page 136-137 of the manual for NI PCI-6220 for the pins for ChA and ChB.
+<pre>
+#include <stdio.h>
+#include <NIDAQmx.h>
+#include <time.h>
+#define DAQmxErrChk(functionCall) if( DAQmxFailed(error=(functionCall)) ) goto Error; else
+int main(void){
+	int32		error=0;
+	TaskHandle	taskHandle=0;
+	int32		read;
+	float64		motorAngle;
+	char		errBuff[2048]={'\0'};
+	int		ii;
+	/*********************************************/
+	// DAQmx Configure Code
+	/*********************************************/
+	DAQmxErrChk(DAQmxCreateTask("EncoderTask",&taskHandle));
+	DAQmxErrChk(DAQmxCreateCIAngEncoderChan(taskHandle,"AnalogIn/ctr0","Counter",DAQmx_Val_X4,0,0.0,DAQmx_Val_AHighBHigh,DAQmx_Val_Degrees,600,36000.0,""));
+	/*********************************************/
+	// DAQmx Start Code
+	/*********************************************/
+	DAQmxErrChk(DAQmxStartTask(taskHandle));
+	/*********************************************/
+	// DAQmx Read Code
+	/*********************************************/
+	for(ii = 0; ii < 2000; ii++){
+		DAQmxErrChk(DAQmxReadCounterF64(taskHandle,1,10.0,&motorAngle,1,&read,NULL));
+		printf("%4d\t%f\n", ii, motorAngle);
 	}

@@ Line 105: / Line 105: @@
 = 12.3us-21.5us (typically 12.6us)<br>
 = 13.1us-24.0us (typically 13.1us)<br>
+<br>
+===Encoder===
+Time it takes to read x encoder inputs.<br>
+= 14.2us-27.6us (typically 14.5us)<br>
 <br>

@@ Line 7: / Line 7: @@
 * [http://sine.ni.com/nips/cds/view/p/lang/en/nid/10702 NI PCI-6713] 12-Bit, 1 MS/s per Channel Analog Output Board
-This wiki document assumes that you have real-time patched SUSE 11.0 operating system installed. You can follow the guide [http://hades.mech.northwestern.edu/index.php/Real-Time_Linux_for_TrackCam here].
+This wiki document assumes that you have real-time patched SUSE 11.0 operating system installed. You can follow the guide [[Real-Time Linux for TrackCam|here]].
 ==Installing Drivers and C-API==

@@ Line 309: / Line 309: @@
 	/*********************************************/
 	for(ii = 0; ii < 2000; ii++){
+		data = ii % 2;
 		DAQmxErrChk(DAQmxWriteDigitalLines(taskHandle,1,TRUE,10.0,DAQmx_Val_GroupByScanNumber,&data,&written,NULL));
 		printf("%4d\t%d\n", ii, data);

@@ Line 99: / Line 99: @@
 ===Digital===
 Time it takes to read x digital inputs.<br>
-line  = 12.0us-22.3us (typically 12.0us)<br>
+= 12.0us-22.3us (typically 12.0us)<br>
-lines = 12.6us-24.9us (typically 12.6us)<br>
+= 12.6us-24.9us (typically 12.6us)<br>
 <br>
 Time it takes to write x digital outputs.<br>
-line  = 12.3us-21.5us (typically 12.6us)<br>
+= 12.3us-21.5us (typically 12.6us)<br>
-lines = 13.1us-24.0us (typically 13.1us)<br>
+= 13.1us-24.0us (typically 13.1us)<br>
 <br>

@@ Line 79: / Line 79: @@
 Here are some experimental timing data.
+===Analog===
-Time it takes to read x analog inputs.
+Time it takes to read x analog inputs.<br>
-= 27.6-42.5us (typically 28.8us)
+= 27.6-42.5us (typically 28.8us)<br>
+= 41.9-55.3us (typically 43.6us)<br>
-= 41.9-55.3us (typically 43.6us)
+= 55.9-72.9us (typically 57.8us)<br>
+= 69.8-86.3us (typically 72.6us)<br>
-= 55.9-72.9us (typically 57.8us)
+= 84.3-100.5us (typically 87.1us)<br>
+= 98.0-124.0us (typically ~101us)<br>
-= 69.8-86.3us (typically 72.6us)
+= 112.0-130.4us (typically ~115us)<br>
+<br>
+Time it takes to write x analog outputs.<br>
-= 84.3-100.5us (typically 87.1us)
+= 12.8-23.2us (typically 13.1us)<br>
-= 98.0-124.0us (typically ~101us)
+= 13.1-23.2us (typically 13.1us)<br>
+= 13.4-23.8us (typically 13.7us)<br>
-= 112.0-130.4us (typically ~115us)
+= 15.1-26.0us (typically 15.4us)<br>
+= 15.9-27.9us (typically 16.2us)<br>
+= 17.6-29.9us (typically 17.9us)<br>
-Time it takes to write x analog outputs.
+= 19.0-32.1us (typically 19.5us)<br>
+===Digital===
-= 12.8-23.2us (typically 13.1us)
+Time it takes to read x digital inputs.<br>
-= 13.1-23.2us (typically 13.1us)
+line  = 12.0us-22.3us (typically 12.0us)<br>
+lines = 12.6us-24.9us (typically 12.6us)<br>
+<br>
-= 13.4-23.8us (typically 13.7us)
+Time it takes to write x digital outputs.<br>
-= 15.1-26.0us (typically 15.4us)
+line  = 12.3us-21.5us (typically 12.6us)<br>
+lines = 13.1us-24.0us (typically 13.1us)<br>
+<br>
-= 15.9-27.9us (typically 16.2us)
-= 17.6-29.9us (typically 17.9us)
-= 19.0-32.1us (typically 19.5us)
-Time it takes to read x digital inputs.
-line  = 12.0us-22.3us (typically 12.0us)
-lines = 12.6us-24.9us (typically 12.6us)
-Time it takes to write x digital outputs.
-line  = 12.3us-21.5us (typically 12.6us)
-lines = 13.1us-24.0us (typically 13.1us)
 ==Example Code==

@@ Line 1: / Line 1: @@
 ==Overview==
 Project by: James Yeung, Master in Electrical and Computer Engineering, 2010.<br>
-Last updated: April 23, 2010
+Last updated: June 11, 2010
 The goal of this project was to get the National Instruments Data Acquisition Cards to work on Linux. More specifically, the two cards that will be documented here are: