Using HDLC/LAP-D Protocol
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 |
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Control Code |
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Packet Length |
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Control Code Defines the action to be taken by this request.
Control Length The 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 allows the following Control Codes:
5 | CW_STATS | Send ST25L2STAT status message |
This control write triggers the protocol to send a ST25L2STAT status message. For the format of this message, see the section on “Status and Error Messages”. Control length must be zero.
6CW_REVCODE Send ST25REVCD status message
This control write triggers the protocol to send a ST25REVCD status message. For the format of this message, see the section on “Status and Error Messages”. Control length must be zero.
30 | Chapter 3 |