User's Manual

24 Chapter3

Using HDLC.FRAME Protocol

Request Specific Processing

Control Requests

All control writes to this protocol share a common format. The first four

bytesaredefinedasaheader

Control Code Defines the action t o 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

transmittedoverthewire)tobepassedtoacontrol

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 t o 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.

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

Control Code Control Length

Packet Length(0)