public static IMemoryOwner <byte> TranslateToMemory(S7ReadJobDatagram datagram, out int memoryLength)
{
var result = S7HeaderDatagram.TranslateToMemory(datagram.Header, out memoryLength);
var mem = result.Memory.Slice(0, memoryLength);
var span = mem.Span;
var offset = datagram.Header.GetHeaderSize();
span[offset++] = datagram.Function;
span[offset++] = datagram.ItemCount;
foreach (var item in datagram.Items)
{
S7AddressItemSpecificationDatagram.TranslateToMemory(item, mem.Slice(offset));
offset += item.GetSpecificationLength();
}
return(result);
}
public static S7ReadJobDatagram TranslateFromMemory(Memory <byte> data)
{
var span = data.Span;
var result = new S7ReadJobDatagram
{
Header = S7HeaderDatagram.TranslateFromMemory(data),
};
var offset = result.Header.GetHeaderSize();
result.Function = span[offset++];
result.ItemCount = span[offset++];
for (var i = 0; i < result.ItemCount; i++)
{
var res = S7AddressItemSpecificationDatagram.TranslateFromMemory(data.Slice(offset));
result.Items.Add(res);
offset += res.GetSpecificationLength();
}
return(result);
}
public static S7ReadJobDatagram BuildRead(SiemensPlcProtocolContext context, int id, IEnumerable <ReadItem> vars)
{
var result = new S7ReadJobDatagram();
result.Header.ProtocolDataUnitReference = (ushort)id;
if (vars != null)
{
foreach (var item in vars)
{
result.Items.Add(new S7AddressItemSpecificationDatagram
{
TransportSize = S7AddressItemSpecificationDatagram.GetTransportSize(item.Area, item.VarType),
ItemSpecLength = item.Length,
DbNumber = item.DbNumber,
Area = (byte)item.Area,
Address = S7AddressItemSpecificationDatagram.GetAddress(item.Offset, item.VarType)
});
}
}
result.Header.ParamLength = (ushort)(2 + result.Items.Count * 12);
result.ItemCount = (byte)result.Items.Count;
return(result);
}