DEFINITION MODULE DataLink;   (* Sends and Receives Packets for PCKermit *)

   FROM PMWIN IMPORT
      MPARAM;
 
   FROM PAD IMPORT
      PacketType;
 
   EXPORT QUALIFIED
      WM_DL, FlushUART, SendPacket, ReceivePacket, DoDLMsg;

   CONST
      WM_DL = 6000H;
 
   PROCEDURE FlushUART;
   (* ensure no characters left in UART holding registers *)
 
   PROCEDURE SendPacket (s : PacketType);
   (* Adds SOH and CheckSum to packet *)
 
   PROCEDURE ReceivePacket (VAR r : PacketType) : BOOLEAN;
   (* strips SOH and checksum -- returns status: TRUE= good packet       *)
   (* received;  FALSE = timed out waiting for packet or checksum error  *)
 
   PROCEDURE DoDLMsg (mp1, mp2 [VALUE] : MPARAM);
   (* Process DataLink Messages *)
 
END DataLink.