A2B: Add A2B message initial support

include/icsneo/communication/packet/a2bpacket.h

@@ -0,0 +1,44 @@
+#ifndef __A2BPACKET_H__
+#define __A2BPACKET_H__
+
+#ifdef __cplusplus
+
+#include "icsneo/api/eventmanager.h"
+#include <cstdint>
+#include <memory>
+#include <optional>
+#include "icsneo/communication/message/message.h"
+
+
+
+namespace icsneo {
+
+typedef uint16_t icscm_bitfield;
+
+struct HardwareA2BPacket {
+
+	static std::shared_ptr<Message> DecodeToMessage(const std::vector<uint8_t>& bytestream);
+
+	struct 
+	{
+		// CxA2B
+		icscm_bitfield channelNum : 8;
+		icscm_bitfield channelSize16 : 1;
+		icscm_bitfield : 7;
+
+		// CxA2B2
+		icscm_bitfield monitor : 1;
+		icscm_bitfield txmsg : 1;
+		icscm_bitfield errIndicator : 1;
+		icscm_bitfield syncFrame : 1;
+		icscm_bitfield upstream : 1;
+		icscm_bitfield : 11;
+		icscm_bitfield rfu2;
+	} header;
+};
+
+}
+
+#endif // __cplusplus
+
+#endif