Hey there,
for my project I need to measure the voltage of a automobile battery with 1kHz.
Therefore I bought a LabJack U3-HV. My plan is to stream the values and add a timestamp.
My plan is to:
- do initializations etc (load necessary .dll, read firmware, check for HV-Version, errorhandling, ...)
- set AIN0 to -10V/+20V range
- initialize the necessary stream
- add timestamps to data
I couldn't figure out how to configure AIN0 to -10V/+20V range:
// configure AIN0 as -10V/+20V ErrorHandler( LJUD.ePut(Handle[0], LJUD.LJ_ioPUT_AIN_RANGE, 0, LJUD.LJ_rgAUTO, 0) , 0, new Exception());
And whether the stream configuration is okay:
// configure the stream: // set the scan rate. ErrorHandler( LJUD.AddRequest(Handle[0], LJUD.LJ_ioPUT_CONFIG, LJUD.LJ_chSTREAM_SCAN_FREQUENCY, scanRate, 0, 0) , 0, new Exception()); // give the driver a 5 second buffer (scanRate * 1 channel * 5 seconds). ErrorHandler( LJUD.AddRequest(Handle[0], LJUD.LJ_ioPUT_CONFIG, LJUD.LJ_chSTREAM_BUFFER_SIZE, scanRate * 1 * 5, 0, 0) , 0, new Exception()); // configure reads to retrieve whatever data is available without waiting (wait mode LJ_swNONE). ErrorHandler( LJUD.AddRequest(Handle[0], LJUD.LJ_ioPUT_CONFIG, LJUD.LJ_chSTREAM_WAIT_MODE, LJUD.LJ_swNONE, 0, 0) , 0, new Exception()); // reset, than define the scan list as AIN0 ErrorHandler( LJUD.AddRequest(Handle[0], LJUD.LJ_ioCLEAR_STREAM_CHANNELS,0, 0, 0, 0) , 0, new Exception()); ErrorHandler( LJUD.AddRequest(Handle[0], LJUD.LJ_ioADD_STREAM_CHANNEL, 0, 0, 0, 0) , 0, new Exception());
When running the code, I get the following output:
LabJack U3-HV: Initialisierung (UD-Treiber v3.35, LJUDJava v0.3((console)), Hardware v1.3((console)), Firmware v1.46)((console)) LabJack U3-HV: Messung läuft, Abtastfrequenz: 1000.0Hz((console))AIN0 = 4,271V, scans: 75, commBacklog = 0 AIN0 = 4,271V, scans: 100, commBacklog = 0 AIN0 = 4,271V, scans: 100, commBacklog = 0 AIN0 = 4,271V, scans: 100, commBacklog = 0 AIN0 = 4,271V, scans: 100, commBacklog = 0 AIN0 = 4,266V, scans: 100, commBacklog = 0 AIN0 = 4,266V, scans: 100, commBacklog = 0 AIN0 = 4,271V, scans: 100, commBacklog = 0 AIN0 = 4,271V, scans: 100, commBacklog = 0 AIN0 = 4,277V, scans: 100, commBacklog = 0 AIN0 = 4,266V, scans: 100, commBacklog = 0 AIN0 = 4,266V, scans: 100, commBacklog = 0 LabJack U3-HV: Messung beendet nach 1.2 Sekunden.((console))
So, it seems to work fine with a 100ms delay with a very stable number of 100 scans?!
----------------------------------------------------------------------------------------------------------------------------------
My complete public void run() - code is:
int Errorcode;
int[] Handle = { 0 };
int GetNextIteration;
int i = 0, k = 0;
int[] IOType = { 0 };
int[] Channel = { 0 };
double[] Value = { 0 };
double[] Backlog = { 0 };
double scanRate = 1000;
long delayms = 100;
double numScans = 2*scanRate*delayms/1000; // 2x the expected # of scans (2*scanRate*delayms/1000) TODO
double[] numScansRequested = { 0 };
double[] adblData = new double[4000]; // Max buffer size (#channels*numScansRequested) TODO
int[] iZero = { 0 };
double[] dZero = { 0 };
NumberFormat formatter = new DecimalFormat("0.000");
// initialization
errorOccured = false;
// application information -> console
PanelConsole.append("\nLabJack U3-HV: Initialisierung (UD-Treiber v" + LJUD.GetDriverVersion() + ", LJUDJava v" + LJUD.LJUDJAVA_VERSION);
// Open the first found LabJack U3-HV and check, whether this was successful
Errorcode = LJUD.OpenLabJack(LJUD.LJ_dtU3, LJUD.LJ_ctUSB, "1", 1, Handle);
if (Errorcode == 1010) {
errorOccured = true;
PanelMeasurementDisplay.setStopMeasurement();
PanelConsole.append("\nFEHLER! LabJack U3-HV wird von einer anderen Anwendung verwendet, Messung wird beendet");
JOptionPane.showMessageDialog(null, "LabJack U3-HV wird von einer anderen Anwendung verwendet, Messung wird beendet!\nBitte entsprechendes Programm beenden!");
} else {
ErrorHandler(Errorcode, 0, new Exception());
}
// if LabJack U3-HV connected, ...
if(!errorOccured) {
// read and display the hardware version of this U3.
ErrorHandler(
LJUD.eGet(Handle[0], LJUD.LJ_ioGET_CONFIG, LJUD.LJ_chHARDWARE_VERSION, Value, 0)
, 0, new Exception());
PanelConsole.append(", Hardware v" + Value[0]);
// read and display the firmware version of this U3.
ErrorHandler(
LJUD.eGet(Handle[0], LJUD.LJ_ioGET_CONFIG, LJUD.LJ_chFIRMWARE_VERSION, Value, 0)
, 0, new Exception());
PanelConsole.append(", Firmware v" + Value[0] + ")");
// check, whether U3 is HV-model
ErrorHandler(
LJUD.eGet(Handle[0], LJUD.LJ_ioGET_CONFIG, LJUD.LJ_chU3HV, Value, 0)
, 0, new Exception());
if(Value[0] == 1) {
// set all pin assignments to the factory default condition
ErrorHandler(
LJUD.ePut(Handle[0], LJUD.LJ_ioPIN_CONFIGURATION_RESET, 0, 0, 0)
, 0, new Exception());
// configure AIN0 as -10V/+20V
ErrorHandler(
LJUD.ePut(Handle[0], LJUD.LJ_ioPUT_AIN_RANGE, 0, LJUD.LJ_rgAUTO, 0)
, 0, new Exception()); //TODO
// configure the stream:
// set the scan rate.
ErrorHandler(
LJUD.AddRequest(Handle[0], LJUD.LJ_ioPUT_CONFIG, LJUD.LJ_chSTREAM_SCAN_FREQUENCY, scanRate, 0, 0)
, 0, new Exception());
// give the driver a 5 second buffer (scanRate * 1 channel * 5 seconds).
ErrorHandler(
LJUD.AddRequest(Handle[0], LJUD.LJ_ioPUT_CONFIG, LJUD.LJ_chSTREAM_BUFFER_SIZE, scanRate * 1 * 5, 0, 0)
, 0, new Exception());
// configure reads to retrieve whatever data is available without waiting (wait mode LJ_swNONE).
ErrorHandler(
LJUD.AddRequest(Handle[0], LJUD.LJ_ioPUT_CONFIG, LJUD.LJ_chSTREAM_WAIT_MODE, LJUD.LJ_swNONE, 0, 0)
, 0, new Exception());
// reset, than define the scan list as AIN0
ErrorHandler(LJUD.AddRequest(Handle[0], LJUD.LJ_ioCLEAR_STREAM_CHANNELS, 0, 0, 0, 0)
, 0, new Exception());
ErrorHandler(LJUD.AddRequest(Handle[0], LJUD.LJ_ioADD_STREAM_CHANNEL, 0, 0, 0, 0)
, 0, new Exception());
// execute the list of requests.
Errorcode = LJUD.GoOne(Handle[0]);
ErrorHandler(Errorcode, 0, new Exception());
// get all the results just to check for errors.
Errorcode = LJUD.GetFirstResult(Handle[0], IOType, Channel, Value, iZero, dZero);
ErrorHandler(Errorcode, 0, new Exception());
GetNextIteration = 0; // Used by the error handling function.
while (Errorcode < LJUD.LJE_MIN_GROUP_ERROR) {
Errorcode = LJUD.GetNextResult(Handle[0], IOType, Channel, Value, iZero, dZero);
if (Errorcode != LJUD.LJE_NO_MORE_DATA_AVAILABLE)
ErrorHandler(Errorcode, GetNextIteration, new Exception());
GetNextIteration++;
}
// start the stream.
ErrorHandler(
LJUD.eGet(Handle[0], LJUD.LJ_ioSTART_STREAM, 0, Value, 0)
, 0, new Exception());
// read actual scan rate and display
PanelConsole.append("\nLabJack U3-HV: Messung läuft, Abtastfrequenz: " + Value[0] + "Hz");
// read data
while (!PanelMeasurementDisplay.getStopMeasurement())
{
// wait for delay in ms
Thread.sleep(delayms);
// init array so we can easily tell if it has changed
for (k = 0; k < numScans * 2; k++)
adblData[k] = 9999.0;
// read the data
numScansRequested[0] = numScans;
ErrorHandler(
LJUD.eGet(Handle[0], LJUD.LJ_ioGET_STREAM_DATA, LJUD.LJ_chALL_CHANNELS, numScansRequested, adblData)
, 0, new Exception());
// display data at the panel
PanelMeasurementDisplay.setVoltage(formatter.format(adblData[0]));
// get backlog
Errorcode = LJUD.eGet(Handle[0], LJUD.LJ_ioGET_CONFIG, LJUD.LJ_chSTREAM_BACKLOG_COMM, Backlog, 0);
// write informations -> console
System.out.println("AIN0 = " + formatter.format(adblData[0])
+ "V, scans: " + (long) numScansRequested[0]
+ ", commBacklog = " + (long) Backlog[0]);
// increment i
i++;
}
}
// Stop the stream
Errorcode = LJUD.eGet(Handle[0], LJUD.LJ_ioSTOP_STREAM, 0, dZero, 0);
if(!errorOccured) {
ErrorHandler(Errorcode, 0, new Exception());
PanelConsole.append("\nLabJack U3-HV: Messung beendet nach " + i/(scanRate/100) + " Sekunden.");
}
} else {
System.out.println("KEIN HV"); //TODO
}
}
