public void CreateTask(IEnumerable <INidaqMetric> nodes)
{
if (TaskHandle != 0)
{
throw new InvalidOperationException("Task already created. First destroy the old task or task already created");
}
if (!nodes.All(n => n is MetricDigitalInput))
{
throw new InvalidCastException("all passed nodes must be of type MetricDigitalInput");
}
if (!nodes.All(n => n.Channel.Device == Device))
{
throw new InvalidOperationException("not all passed nodes are connected to device " + Device.Name);
}
// 1. create task
if (Source == ClockSource.Intern)
{
_counter = new NidaqCounterOutput(Device.Name + "/ctr0", ClockRate);
}
var taskHandle = new int[1];
var result = NidaQmxHelper.DAQmxCreateTask(null, taskHandle);
if (result < 0)
{
throw new NidaqException(result);
}
TaskHandle = taskHandle[0];
// 2. create channels
foreach (var input in nodes.OfType <MetricDigitalInput>())
{
result = NidaQmxHelper.DAQmxCreateDIChan(
lines: input.Channel.Path,
taskHandle: TaskHandle,
lineGrouping: NidaQmxHelper.DAQmx_Val_ChanForAllLines,
nameToAssignToChannel: null
);
if (result < 0)
{
CleanupAndThrow(result);
}
_nodes.Add(input);
}
// 3. configure clock
SamplesPerChannel = ClockRate / 10;
result = NidaQmxHelper.DAQmxCfgSampClkTiming(
activeEdge: NidaQmxHelper.DaQmxValRising,
sampleMode: NidaQmxHelper.DaQmxValContSamps,
sampsPerChan: (ulong)SamplesPerChannel,
taskHandle: TaskHandle,
source: (this.Source == ClockSource.Intern) ? ("/" + Device.Name + "/Ctr0InternalOutput") : ClockPath,
rate: ClockRate
);
if (result < 0)
{
CleanupAndThrow(result);
}
State = SessionTaskState.Stopped;
}