public static async Task <string> QueryValueAsync(AmsNetId target, string subKey, string valueName)
{
using (AdsClient client = new AdsClient())
{
client.Connect(new AmsAddress(target, AmsPort.SystemService));
var readBuffer = new Memory <byte>(new byte[255]);
var data = new List <byte>();
data.AddRange(System.Text.Encoding.UTF8.GetBytes(subKey));
data.Add(new byte()); // End delimiter
data.AddRange(System.Text.Encoding.UTF8.GetBytes(valueName));
data.Add(new byte());
var writeBuffer = new ReadOnlyMemory <byte>(data.ToArray());
var result = await client.ReadWriteAsync(200, 0, readBuffer, writeBuffer, CancellationToken.None);
result.ThrowOnError();
return(System.Text.Encoding.UTF8.GetString(readBuffer.ToArray(), 0, result.ReadBytes));
}
}