User's Manual

Product Manual - RFID Reader LF60C SoliD 73
Chapter 7
Operation
HSMS message
header
The message header is a 10-byte field. The bytes in the header are numbered
from byte 0 (first byte transmitted) to byte 9. The format of the message header
is as follows:
The physical byte order is designed to correspond as closely as possible to the
SECS-I header.
The session ID is a 16-bit unsigned integer value, which occupies bytes 0 and 1 of
the header (byte 0 is MSB). Its purpose is to provide an association by reference
between control messages and subsequent messages.
Header byte 2 is used in different ways for different HSMS messages. For control
messages, it contains 0 or a status code. For a data message, it contains the W
bit and SECS stream.
Header byte 3 contains 0 or a status code for control messages. For data
messages, it contains the SECS function.
P-type is an 8-bit unsigned integer value which occupies byte 4 of the message
header; message header and message text are encoded. Only P-type = 0 is
defined by HSMS to mean SECS-II message encoding. For non-zero P-type
values, see SEMI E37.
Bytes Description
0-1 Session ID (Device ID)
2Header byte 2
3Header byte 3
4P-type
5S-type
6-9 System bytes