`CONSTANTS` (GVL)

InOut:

Name	Type	Initial	Comment
abyBroadcastMAC	ARRAY [0..5] OF BYTE	[16#FF, 16#FF, 16#FF, 16#FF, 16#FF, 16#FF]
wHardwareType	`WORD`	16#1
wProtocolType	`WORD`	16#800
wOpcodeRequest	`WORD`	16#1
wOpcodeResponse	`WORD`	16#2
wARPEthType	`WORD`	16#806	Ether types
wVLANEthType	`WORD`	16#8100