Handling Out Of Range Errors - Revision history

Mparadis at 19:22, 14 July 2023

2023-07-14T19:22:35Z

← Older revision		Revision as of 19:22, 14 July 2023
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			{{#seo:\|description=Your code should respond to Out of Range errors to provide uninterrupted data. This page will guide you through the different ways to handle these errors.}}
	__TOC__		__TOC__
	==Intro==		==Intro==

Jdecoux: /* Intro */

2023-07-14T16:59:15Z

Intro

← Older revision		Revision as of 16:59, 14 July 2023
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	==Intro==		==Intro==
	All new Phidgets have been designed to seamlessly and informatively communicate problems with measured data. This allows you to more easily debug your systems, while ensuring data events from sensors continue at a steady pace. This makes it possible to use data events as a reliable time-base for your system.		All new Phidgets have been designed to seamlessly and informatively communicate problems with measured data. This allows you to more easily debug your systems, while ensuring data events from sensors continue at a steady pace. This makes it possible to use data events as a reliable time-base for your system.

			<center>[[Image:OutOfRangeErrorSampleGraph.png\|400px\|Center\|link=\|]]</center>

	To understand the more technical points of this article, we recommend first learning about [[Phidget Programming Basics]].		To understand the more technical points of this article, we recommend first learning about [[Phidget Programming Basics]].

Jdecoux at 16:34, 14 July 2023

2023-07-14T16:34:57Z

@@ Line 129: / Line 129: @@
 |-|
 Sample Output=
 Press Enter to Stop
 Temperature: 14.062
@@ Line 156: / Line 157: @@
 Temperature: 16.978
 Temperature: 17.214
 </tabber>
@@ Line 251: / Line 253: @@
+	}
+}
 </syntaxhighlight>
 </tabber>
@@ Line 348: / Line 368: @@
+	}
+}
 </syntaxhighlight>
 </tabber>

Jdecoux: /* Data Events */

2023-07-14T16:14:00Z

Data Events

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+}
 </syntaxhighlight>
 </tabber>

Jdecoux: Created page with "TOC ==Intro== All new Phidgets have been designed to seamlessly and informatively communicate problems with measured data. This allows you to more easily debug your systems, while ensuring data events from sensors continue at a steady pace. This makes it possible to use data events as a reliable time-base for your system. To understand the more technical points of this article, we recommend first learning about Phidget Programming Basics. ==Data Events== All mo..."

2023-07-13T16:05:50Z

Created page with "__TOC__ ==Intro== All new Phidgets have been designed to seamlessly and informatively communicate problems with measured data. This allows you to more easily debug your systems, while ensuring data events from sensors continue at a steady pace. This makes it possible to use data events as a reliable time-base for your system. To understand the more technical points of this article, we recommend first learning about Phidget Programming Basics. ==Data Events== All mo..."

New page

__TOC__
==Intro==
All new Phidgets have been designed to seamlessly and informatively communicate problems with measured data. This allows you to more easily debug your systems, while ensuring data events from sensors continue at a steady pace. This makes it possible to use data events as a reliable time-base for your system.

To understand the more technical points of this article, we recommend first learning about [[Phidget Programming Basics]].

==Data Events==
All modern Phidgets guarantee that data events will occur on a channel at the user-defined rate, or will inform you of the actual data rate if it is unable to keep up. This remains true even if the data on the channel is unknown or invalid.

Values from a sensor that are too high or too low to be accurately measured will be capped slightly outside the specified Minimum and Maximum values for the sensor. For example, if a temperature sensor can measure from -30°C to 85°C, you can expect values outside of this range to all read as -31°C and 86°C, respectively. You can monitor for these out-of-range indicators by checking the value from the event against the minimum and maximum values for the sensor.

Values that are strictly unknown for one reason or another, such as a probe being unplugged, will be reported as ''NaN'' in the related event handler. Be sure your code is robust enough to handle this possibility.

<tabber>
Python=
<syntaxhighlight lang=python>
from Phidget22.Phidget import *
from Phidget22.Devices.TemperatureSensor import *
import math
import time

def onTemperatureChange(self, temperature):
if(math.isnan(temperature)):
print("Temperature is unknown")
elif(temperature > self.getMaxTemperature()):
print("Temperature is too high")
elif(temperature < self.getMinTemperature()):
print("Temperature is too low")
else:
print("Temperature: " + str(temperature))

def main():
temperatureSensor0 = TemperatureSensor()

temperatureSensor0.setOnTemperatureChangeHandler(onTemperatureChange)

temperatureSensor0.openWaitForAttachment(5000)

try:
input("Press Enter to Stop\n")
except (Exception, KeyboardInterrupt):
pass

temperatureSensor0.close()

main()
</syntaxhighlight>
|-|
Java=
<syntaxhighlight lang=java>
import com.phidget22.*;
import java.util.Scanner; //Required for Text Input
import java.io.IOException;

public class Java_Example {

public static void main(String[] args) throws Exception {
TemperatureSensor temperatureSensor0 = new TemperatureSensor();

temperatureSensor0.addTemperatureChangeListener(new
TemperatureSensorTemperatureChangeListener() {
public void onTemperatureChange(TemperatureSensorTemperatureChangeEvent e) {
try {
if(Double.isNaN(e.getTemperature()))
System.out.println("Temperature is unknown");
else if(e.getTemperature() > temperatureSensor0.getMaxTemperature())
System.out.println("Temperature is too high");
else if(e.getTemperature() < temperatureSensor0.getMinTemperature())
System.out.println("Temperature is too low");
else
System.out.println("Temperature: " + e.getTemperature());
} catch (PhidgetException ex) {
System.out.println("PhidgetException " +
ex.getErrorCode() + " (" + ex.getDescription() + "): " +
ex.getDetail());
}
}
});

temperatureSensor0.open(5000);

//Wait until Enter has been pressed before exiting
System.in.read();

temperatureSensor0.close();
}
}
</syntaxhighlight>
|-|
C#=
<syntaxhighlight lang=cSharp>
using System;
using Phidget22;

namespace ConsoleApplication
{
class Program
{

private static void TemperatureSensor0_TemperatureChange(object sender, Phidget22.Events.TemperatureSensorTemperatureChangeEventArgs e)
{
TemperatureSensor ch = (TemperatureSensor)sender;
if (Double.IsNaN(e.Temperature))
Console.WriteLine("Temperature is unknown");
else if (e.Temperature > ch.MaxTemperature)
Console.WriteLine("Temperature is too high");
else if (e.Temperature < ch.MinTemperature)
Console.WriteLine("Temperature is too low");
else
Console.WriteLine("Temperature: " + e.Temperature);
}

static void Main(string[] args)
{
TemperatureSensor temperatureSensor0 = new TemperatureSensor();

temperatureSensor0.TemperatureChange += TemperatureSensor0_TemperatureChange;

temperatureSensor0.Open(5000);

//Wait until Enter has been pressed before exiting
Console.ReadLine();

temperatureSensor0.Close();
}
}
}
</syntaxhighlight>
</tabber>

==Polling==
When polling for data, values that are unknown, too high, or too low will give relevant return codes or exceptions, typically '''UNKNOWNVALUE''', '''UNKNOWNVALUEHIGH''', or '''UNKNOWNVALUELOW''' respectively.

In most programming languages (excluding C), specific information about the error will be available to the exception handler to help identify the specifics of the error.

For information on how to see error messages in C, look up ''Phidget_getLastError'' in the API.

<tabber>
Python=
<syntaxhighlight lang=python>
from Phidget22.Phidget import *
from Phidget22.Devices.TemperatureSensor import *
import math
import time

def main():
temperatureSensor0 = TemperatureSensor()

temperatureSensor0.openWaitForAttachment(5000)

for i in range(1, 10):
try:
print(temperatureSensor0.getTemperature())
except PhidgetException as ex:
print("PhidgetException " + str(ex.code) + " (" + ex.description + "): " + ex.details)
time.sleep(1)

temperatureSensor0.close()

main()
</syntaxhighlight>
|-|
Java=
<syntaxhighlight lang=java>
import com.phidget22.*;
import java.util.Scanner; //Required for Text Input
import java.io.IOException;

public class Java_Example {

public static void main(String[] args) throws Exception {
TemperatureSensor temperatureSensor0 = new TemperatureSensor();

temperatureSensor0.open(5000);

while(System.in.available() == 0) {
try {
System.out.println(temperatureSensor0.getTemperature());
} catch (PhidgetException ex) {
System.out.println("PhidgetException " +
ex.getErrorCode() + " (" + ex.getDescription() + "): " +
ex.getDetail());
}
Thread.sleep(1000);
}

temperatureSensor0.close();
}
}
</syntaxhighlight>
|-|
C#=
<syntaxhighlight lang=cSharp>
using System;
using Phidget22;

namespace ConsoleApplication
{
class Program
{
static void Main(string[] args)
{
TemperatureSensor temperatureSensor0 = new TemperatureSensor();

temperatureSensor0.Open(5000);

while(Console.KeyAvailable == false)
{
try
{
Console.WriteLine("Temperature: " + temperatureSensor0.Temperature);
}
catch (PhidgetException ex)
{
Console.WriteLine("PhidgetException " + ex.ErrorCode +
" (" + ex.Description + "): " + ex.Detail);
}
System.Threading.Thread.Sleep(1000);
}
temperatureSensor0.Close();
}
}
}
</syntaxhighlight>
</tabber>

==Error Events==
In addition to data events, you can use error event handlers to get specific information about error conditions as they happen. A single error event handler will provide meaningful information in text form about each error condition as it happens. These have been standardized to occur once every second for as long as the error condition persists.

If your system has older Phidgets, this method may be the only way to access additional error information.

<tabber>
Python=
<syntaxhighlight lang=python>
from Phidget22.Phidget import *
from Phidget22.Devices.TemperatureSensor import *
import time

def onError(self, code, description):
print("Code: " + ErrorEventCode.getName(code))
print("Description: " + str(description))
print("----------")

def main():
temperatureSensor0 = TemperatureSensor()

temperatureSensor0.setOnErrorHandler(onError)

temperatureSensor0.openWaitForAttachment(5000)

try:
input("Press Enter to Stop\n")
except (Exception, KeyboardInterrupt):
pass

temperatureSensor0.close()

main()
</syntaxhighlight>
|-|
Java=
<syntaxhighlight lang=java>
import com.phidget22.*;
import java.lang.InterruptedException;

public class Java_Example {

public static void main(String[] args) throws Exception {
TemperatureSensor temperatureSensor0 = new TemperatureSensor();

temperatureSensor0.addErrorListener(new ErrorListener() {
public void onError(ErrorEvent e) {
System.out.println("Code: " + e.getCode().name());
System.out.println("Description: " + e.getDescription());
System.out.println("----------");
}
});

temperatureSensor0.open(5000);

//Wait until Enter has been pressed before exiting
System.in.read();

temperatureSensor0.close();
}
}
</syntaxhighlight>
|-|
C#=
<syntaxhighlight lang=cSharp>
using System;
using Phidget22;

namespace ConsoleApplication
{
class Program
{

private static void TemperatureSensor0_Error(object sender, Phidget22.Events.ErrorEventArgs e)
{
Console.WriteLine("Code: " + e.Code);
Console.WriteLine("Description: " + e.Description);
Console.WriteLine("----------");
}

static void Main(string[] args)
{
TemperatureSensor temperatureSensor0 = new TemperatureSensor();

temperatureSensor0.Error += TemperatureSensor0_Error;

temperatureSensor0.Open(5000);

//Wait until Enter has been pressed before exiting
Console.ReadLine();

temperatureSensor0.Close();
}
}
}
</syntaxhighlight>
</tabber>