// This example measures the time needed to read 2000 items all at once, and in 20 groups by 100 items.
using System;
using System.Diagnostics;
using System.Threading;
using OpcLabs.EasyOpc.DataAccess;
using OpcLabs.EasyOpc.DataAccess.OperationModel;
namespace DocExamples.DataAccess._EasyDAClient
{
partial class ReadMultipleItems
{
const int NumberOfGroups = 100;
const int ItemsInGroup = 20;
private const int TotalItems = NumberOfGroups * ItemsInGroup;
// Main method
public static void TimeMeasurements()
{
// Make the measurements 10 times; note that first time the times might be longer.
for (int i = 1; i <= 10; i++)
{
// Pause - we do not want the component to use the values it has in memory
Thread.Sleep(2 * 1000);
// Read all items at once, and measure the time
var stopwatch1 = new Stopwatch();
stopwatch1.Start();
ReadAllAtOnce();
stopwatch1.Stop();
Console.WriteLine("ReadAllAtOnce has taken (milliseconds): {0}", stopwatch1.ElapsedMilliseconds);
// Pause - we do not want the component to use the values it has in memory
Thread.Sleep(2 * 1000);
// Read items in groups, and measure the time
var stopwatch2 = new Stopwatch();
stopwatch2.Start();
ReadInGroups();
stopwatch2.Stop();
Console.WriteLine("ReadInGroups has taken (milliseconds): {0}", stopwatch2.ElapsedMilliseconds);
}
// Example output (measured with Version 5.20, Release configuration):
/*
ReadAllAtOnce has taken (milliseconds): 3432
ReadInGroups has taken (milliseconds): 1563
ReadAllAtOnce has taken (milliseconds): 539
ReadInGroups has taken (milliseconds): 1625
ReadAllAtOnce has taken (milliseconds): 579
ReadInGroups has taken (milliseconds): 1594
ReadAllAtOnce has taken (milliseconds): 638
ReadInGroups has taken (milliseconds): 1610
...
*/
// Note that Version 5.12 and earlier were yielding much larger penalty to repeated reads.
// Example output (measured with Version 5.12, Release configuration):
/*
ReadAllAtOnce has taken (milliseconds): 4241
ReadInGroups has taken (milliseconds): 8094
ReadAllAtOnce has taken (milliseconds): 269
ReadInGroups has taken (milliseconds): 7813
ReadAllAtOnce has taken (milliseconds): 285
ReadInGroups has taken (milliseconds): 7813
ReadAllAtOnce has taken (milliseconds): 283
ReadInGroups has taken (milliseconds): 7844
...
*/
}
// Read all items at once
private static void ReadAllAtOnce()
{
// Instantiate the client object.
var client = new EasyDAClient();
// Create an array of item descriptors for all items
var itemDescriptors = new DAItemDescriptor[TotalItems];
int index = 0;
for (int iLoop = 0; iLoop < NumberOfGroups; iLoop++)
for (int iItem = 0; iItem < ItemsInGroup; iItem++)
itemDescriptors[index++] = new DAItemDescriptor(
String.Format("Simulation.Incrementing.Copy_{0}.Phase_{1}", iLoop + 1, iItem + 1));
// Perform the OPC read
DAVtqResult[] vtqResults = client.ReadMultipleItems("OPCLabs.KitServer.2", itemDescriptors);
// Count successful results
int successCount = 0;
for (int iItem = 0; iItem < TotalItems; iItem++)
{
Debug.Assert(vtqResults[iItem] != null);
if (vtqResults[iItem].Succeeded)
successCount++;
}
if (successCount != TotalItems)
Console.WriteLine("Warning: There were some failures, success count is {0}", successCount);
}
// Read items in groups
private static void ReadInGroups()
{
var client = new EasyDAClient();
int successCount = 0;
for (int iLoop = 0; iLoop < NumberOfGroups; iLoop++)
{
// Create an array of item descriptors for items in one group
var itemDescriptors = new DAItemDescriptor[ItemsInGroup];
for (int iItem = 0; iItem < ItemsInGroup; iItem++)
itemDescriptors[iItem] = new DAItemDescriptor(
String.Format("Simulation.Incrementing.Copy_{0}.Phase_{1}", iLoop + 1, iItem + 1));
// Perform the OPC read
DAVtqResult[] vtqResults = client.ReadMultipleItems("OPCLabs.KitServer.2", itemDescriptors);
// Count successful results (totalling to previous value)
for (int iItem = 0; iItem < ItemsInGroup; iItem++)
{
Debug.Assert(vtqResults[iItem] != null);
if (vtqResults[iItem].Succeeded) successCount++;
}
}
if (successCount != TotalItems)
Console.WriteLine("Warning: There were some failures, success count is {0}", successCount);
}
}
}
' This example measures the time needed to read 2000 items all at once, and in 20 groups by 100 items.
Imports System.Threading
Imports OpcLabs.EasyOpc.DataAccess
Imports OpcLabs.EasyOpc.DataAccess.OperationModel
Namespace DataAccess._EasyDAClient
Partial Friend Class ReadMultipleItems
Private Const NumberOfGroups As Integer = 100
Private Const ItemsInGroup As Integer = 20
Private Const TotalItems As Integer = NumberOfGroups * ItemsInGroup
' Main method
Public Shared Sub TimeMeasurements()
' Make the measurements 10 times; note that first time the times might be longer.
For i As Integer = 1 To 10
' Pause - we do not want the component to use the values it has in memory
Thread.Sleep(2 * 1000)
' Read all items at once, and measure the time
Dim stopwatch1 = New Stopwatch()
stopwatch1.Start()
ReadAllAtOnce()
stopwatch1.Stop()
Console.WriteLine("ReadAllAtOnce has taken (milliseconds): {0}", stopwatch1.ElapsedMilliseconds)
' Pause - we do not want the component to use the values it has in memory
Thread.Sleep(2 * 1000)
' Read items in groups, and measure the time
Dim stopwatch2 = New Stopwatch()
stopwatch2.Start()
ReadInGroups()
stopwatch2.Stop()
Console.WriteLine("ReadInGroups has taken (milliseconds): {0}", stopwatch2.ElapsedMilliseconds)
Next i
' Example output (measured with Version 5.20, Release configuration):
'
' ReadAllAtOnce has taken (milliseconds): 3432
' ReadInGroups has taken (milliseconds): 1563
' ReadAllAtOnce has taken (milliseconds): 539
' ReadInGroups has taken (milliseconds): 1625
' ReadAllAtOnce has taken (milliseconds): 579
' ReadInGroups has taken (milliseconds): 1594
' ReadAllAtOnce has taken (milliseconds): 638
' ReadInGroups has taken (milliseconds): 1610
' ...
'
' Note that Version 5.12 and earlier were yielding much larger penalty to repeated reads.
' Example output (measured with Version 5.12, Release configuration):
'
' ReadAllAtOnce has taken (milliseconds): 4241
' ReadInGroups has taken (milliseconds): 8094
' ReadAllAtOnce has taken (milliseconds): 269
' ReadInGroups has taken (milliseconds): 7813
' ReadAllAtOnce has taken (milliseconds): 285
' ReadInGroups has taken (milliseconds): 7813
' ReadAllAtOnce has taken (milliseconds): 283
' ReadInGroups has taken (milliseconds): 7844
' ...
'
End Sub
' Read all items at once
Private Shared Sub ReadAllAtOnce()
Dim client = New EasyDAClient()
' Create an array of item descriptors for all items
Dim itemDescriptors = New DAItemDescriptor(TotalItems - 1) {}
Dim index As Integer = 0
For iLoop As Integer = 0 To NumberOfGroups - 1
For iItem As Integer = 0 To ItemsInGroup - 1
itemDescriptors(index) = New DAItemDescriptor(String.Format("Simulation.Incrementing.Copy_{0}.Phase_{1}", iLoop + 1, iItem + 1))
index += 1
Next iItem
Next iLoop
' Perform the OPC read
Dim vtqResults() As DAVtqResult = client.ReadMultipleItems("OPCLabs.KitServer.2", itemDescriptors)
' Count successful results
Dim successCount As Integer = 0
For iItem As Integer = 0 To TotalItems - 1
Debug.Assert(vtqResults(iItem) IsNot Nothing)
If vtqResults(iItem).Succeeded Then
successCount += 1
End If
Next iItem
If successCount <> TotalItems Then
Console.WriteLine("Warning: There were some failures, success count is {0}", successCount)
End If
End Sub
' Read items in groups
Private Shared Sub ReadInGroups()
Dim client = New EasyDAClient()
Dim successCount As Integer = 0
For iLoop As Integer = 0 To NumberOfGroups - 1
' Create an array of item descriptors for items in one group
Dim itemDescriptors = New DAItemDescriptor(ItemsInGroup - 1) {}
For iItem As Integer = 0 To ItemsInGroup - 1
itemDescriptors(iItem) = New DAItemDescriptor(String.Format("Simulation.Incrementing.Copy_{0}.Phase_{1}", iLoop + 1, iItem + 1))
Next iItem
' Perform the OPC read
Dim vtqResults() As DAVtqResult = client.ReadMultipleItems("OPCLabs.KitServer.2", itemDescriptors)
' Count successful results (totalling to previous value)
For iItem As Integer = 0 To ItemsInGroup - 1
Debug.Assert(vtqResults(iItem) IsNot Nothing)
If vtqResults(iItem).Succeeded Then
successCount += 1
End If
Next iItem
Next iLoop
If successCount <> TotalItems Then
Console.WriteLine("Warning: There were some failures, success count is {0}", successCount)
End If
End Sub
End Class
End Namespace
