AdsBinaryReader.ReadPlcAnsiString Method
Reads a PLC string from the current stream (Encoding.Default, ANSI Encoding)
Namespace: TwinCAT.Ads
Assembly: TwinCAT.Ads (in TwinCAT.Ads.dll)
Version: 4.3.0.0
Syntax
C#
public string ReadPlcAnsiString(
int byteLength
)
VB
Public Function ReadPlcAnsiString (
byteLength As Integer
) As String
Parameters
|
byteLength |
Type: System.Int32 |
Return Value
Type: String
The string being read (until the first '\0'
character)
Remarks
The byte length of a STRING[80] in the PLC is 81. The byte length of a WSTRING[80] in the PLC is 162. Because of ANSI Encoding the number of Chars could differ with the number of Bytes (e.g on Double Byte Codepages DBCS, Codepage 932, Japan)
Examples
The following code shows how to Read/Write ANSI string values..
Read/Write Strings
using (TcAdsClient client = new TcAdsClient())
{
client.Connect(851); // Connect to local port 851 (PLC)
int handle = client.CreateVariableHandle("MAIN.string"); // Symbol "string" in MAIN defined as string
try
{
// Read ANSI String string[80]
int byteSize = 81; // Size of 80 ANSI chars + /0 (STRING[80])
AdsStream readStream = new AdsStream(byteSize); // Size of 80 ANSI chars + /0 (STRING[80])
AdsBinaryReader reader = new AdsBinaryReader(readStream);
client.Read(handle, readStream, 0, byteSize); // Read 81 bytes
string value = reader.ReadPlcString(byteSize,Encoding.Default);
// Write ANSI String string[80]
AdsStream writeStream = new AdsStream(byteSize);
AdsBinaryWriter writer = new AdsBinaryWriter(writeStream);
value = "Changed";
writer.WritePlcString(value, 80,Encoding.Default); // Max 80 characters!
client.Write(handle, writeStream, 0, byteSize);
}
finally
{
client.DeleteVariableHandle(handle);
}
}