User's Manual

OPERATION 5
33
HF5x Transponder Reader (SECS1-Protocol), Release 1.4
Upper Device ID
Lower Device ID
Direction reader to host: 0x81xx *
Direction Host to equipment (BROOKS HF5x reader): 0x01xx *
* … the serial number is located on a label on the housing lid of each
reader
The W-Bit indicates that the sender of a primary message expects a
reply. A value of one in the W-bit means that a reply is expected.
The message ID identifies the format and content of the message being
sent.
A primary message is defined as any odd-numbered message.
A secondary message is defined as any even-numbered message.
The end bit determines whether a block is the last block of the
message. A value of 1 means that the block is the last block.
A message sent as more than one block is called a multi-block
message. A block number of one is given to the first block, and the
block number is incremented by one for each subsequent block until
the entire message is sent.
As all messages can be sent in one block, the block number always has
the value 1.
The system bytes in the header of each message for a given device ID
must meet the following requirements:
 The system bytes of a primary message must be distinct from those
bytes of all currently open transactions initiated from the same end
of the communications link.
 The system bytes of the reply message are required to be the same
as the system bytes of the corresponding primary message.
The system bytes are incremented for each primary message.
The checksum is calculated as the numeric sum of the unsigned binary
values of all the bytes, after the length byte and before the checksum in
a single block.
5.3.2.4 Block Transfer Protocol
The drawing below illustrates some simple message interactions
between the host and the equipment. The figure shows the handshake
sequence possible to acquire the status of the equipment.
serial number of the reader
R-Bit 0 0 0 0 0 0 1