HP Advanced Communications Controllers (ACC) manual Message Request Header zmrqtype

ZCOM Tables and Data Structures

Message Header

MTAGW1, MTAGW2 - Message tag words

These are application defined tag words that are passed unaltered through the ZCOM subsystem with the message data. They are supplied in the zsend and zcntl calls and returned in the zread call. When a receive message is returned from a terminal, the tag words are set to zero.

MZAUXL - Auxiliary ZCOM address

When using the multiplexed mode of operation through the logical terminal table, this field stores the original source ZLU.

Message Request Header (zmrq_type)

The six-byte message request block may or may not be present, depending on the message type and whether it is destined for a terminal. For request types 1, 4, and 6, to a terminal, the request block will be present; for request types 2 and 7 the request block will contain meaningless data. More information on the contents of this block can be found in the firmware reference manual. The Message Request Header is always present. For message types 2, 3, 7, 10, 11, and 15, it contains meaningless data. For types 4, 6, 12, and 14, it contains valid data.

Table 3-38	Message Request Header (zmrq_type)
Field Name		Field Description	Field Type	Size
				(Bytes)
MRQCODE		Request code	uns.char	1
MRQTERM		Terminal number	uns.char	1
MRQSTAT		Request status	uns.char	1
MRQTAG		Tag parameter	uns.char	1
MRQLEN		Data length	uns.short	2
	MRQCODE - Terminal request code

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