private async void thread_test2( )
{
int count = 500;
while (count > 0)
{
if (!(await melsec_net.WriteAsync("D100", (short)1234)).IsSuccess)
{
failed++;
}
if (!(await melsec_net.ReadInt16Async("D100")).IsSuccess)
{
failed++;
}
count--;
}
thread_end( );
}