HP UX 11.x Operating Systems manual Request Specific Processing, Control Requests

Using HDLC.FRAME Protocol

Request Specific Processing

Request Specific Processing

Control Requests

All control writes to this protocol share a common format. The first four bytes are defined as a header

15	14	13	12		11	10	9		8	7	6	5	4	3	2	1	0
Control Code										Control Length
Packet Length(0)
				Control Code				Defines the action to be taken by this request.
				Control Length				The byte length of the data for this control request.
								This data immediately follows the header.
				Packet Length				Some protocols allow packet data (data to be
								transmitted over the wire) to be passed to a control
								write following the control request data. For this
								protocol, these two bytes must be zero because the
								protocol does not allow packet data within a control
								write.

This protocol supports the following Control Code:

5 CW_STATS	Send IO_STATS status message
	This control write triggers the protocol to send an
	IO_STATS status message. For the format of this
	message, see the section on “Status and Error
	Messages”. The control length is zero.

Note that the Non-E1/T1 version of this protocol must have Control Write processing enabled, in order to be able to process Control Write requests. See the “Terminal Definitions” section of Chapter 4 , “Protocol Specific Configuration,” for details.

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