NI 9252 measured current . In NationalInstruments.DAQmx Lib,there are some places where the official explanation is incomprehensible.

[Lane_Zaichen]

When i use NI 9252 to measure current ,I clicked in method:

-->myTask.AIChannels.CreateCurrentChannel(physicalChannelComboBox.Text,"",
(AITerminalConfiguration)(-1), Convert.ToDouble(minimumValueNumeric.Value),
Convert.ToDouble(maximumValueNumeric.Value), AICurrentUnits.Amps);

-->myTask.AIChannels.CreateCurrentChannel(physicalChannelComboBox.Text,"",
(AITerminalConfiguration)(-1), Convert.ToDouble(minimumValueNumeric.Value),
Convert.ToDouble(maximumValueNumeric.Value), Convert.ToDouble(shuntResistorNumeric.Value),
AICurrentUnits.Amps);

And found an explanation of the method,but i don`t know below:

javascript:LaunchMergedHelp('daqhelp.chm','measfunds.chm::/groundSig.html');

Here's a detailed explanation：

// Summary:
// Creates an NationalInstruments.DAQmx.AIChannel with the specified external shunt
// resistor to javascript:LaunchHelp('daqhelp.chm::/Measuring_Current.html');. This
// method adds one or more physical channels to the NationalInstruments.DAQmx.AIChannelCollection.
//
// Parameters:
// physicalChannelName:
// The names of one or more javascript:LaunchMergedHelp('daqhelp.chm','mxcncpts.chm::/Chans.html');
// to use to create one or more local virtual channels.
//
// nameToAssignChannel:
// One or more names to assign to the created local virtual channels. To use the
// physical channel name as the local virtual channel name, set this value to System.String.Empty.
//
// terminalConfiguration:
// The javascript:LaunchMergedHelp('daqhelp.chm','measfunds.chm::/groundSig.html');.
// To use the default terminal configuration for the physical channel(s) being used,
// pass a value of -1 casted to an NationalInstruments.DAQmx.AITerminalConfiguration.
//
// minimumValue:
// The javascript:LaunchMergedHelp('daqhelp.chm','measfunds.chm::/limitSettings.html');
// expected from the measurement, in units.
//
// maximumValue:
// The javascript:LaunchMergedHelp('daqhelp.chm','measfunds.chm::/limitSettings.html');
// expected from the measurement, in units.
//
// externalShuntResistorValue:
// The value in ohms of an external shunt resistor.
//
// units:
// The units to use to return the measurement.
//
// Returns:
// The newly created NationalInstruments.DAQmx.AIChannel.
//
// Exceptions:
// T:NationalInstruments.DAQmx.DaqException:
// The NI-DAQmx driver returned an error.
//
// Remarks:
// This method creates a local virtual channel for every physical channel name you
// specify. If you create multiple local virtual channels with one call to this
// method, you can specify a comma-delimited list of names for nameToAssignChannel.
// If you provide fewer local virtual channel names in nameToAssignChannel than
// you create, NI-DAQmx javascript:LaunchMergedHelp('daqhelp.chm','mxcncpts.chm::/nameAssignment.html');
// to the local virtual channels.
// If you do not provide a value for nameToAssignChannel, NI-DAQmx uses the physicalChannelName
// as the local virtual channel name. If you use nameToAssignChannel to create a
// name for the local virtual channel, you must use this name in other properties
// and methods.
// Use this method with devices that do not have a built-in shunt resistor. You
// must attach an external shunt resistor.
// The NI-DAQmx driver does not determine if the requested settings are possible
// until the task is verified. NationalInstruments.DAQmx.AIChannelCollection.CreateCurrentChannel(System.String,System.String,NationalInstruments.DAQmx.AITerminalConfiguration,System.Double,System.Double,System.Double,NationalInstruments.DAQmx.AICurrentUnits)
// does not throw an exception for parameter values that are not compatible with
// your hardware or other settings in your task. To determine if all of the settings
// for a NationalInstruments.DAQmx.Task are valid, you must verify the task by starting
// the task, either with NationalInstruments.DAQmx.Task.Start or by reading from
// or writing to the task, or by calling NationalInstruments.DAQmx.Task.Control(NationalInstruments.DAQmx.TaskAction)
// with NationalInstruments.DAQmx.TaskAction.Verify.
public AIChannel CreateCurrentChannel(string physicalChannelName, string nameToAssignChannel, AITerminalConfiguration terminalConfiguration, double minimumValue, double maximumValue, double externalShuntResistorValue, AICurrentUnits units);