Brooks Automation
64
278580 Revision A
7 Operation
LF80C ZeniD RFID Reader
7.3 Operation of SECS Protocol
Product Manual
short period, such as may be required for high-speed functional test
applications.
In a network, the roles of host and equipment may be assumed by any
party of the network. In this situation, one end of the communications link
must assume the role of the equipment and the other the role of the host.
Electronic Industries Association Standards:
EIA RS-232-C Interface between Data Terminal Equipment and Data
Communication Equipment Employing Serial Binary Data Interchange.
7.3.2
SECS-I Implementation
This message set describes the communication between a SECS-I reader
and a host. The host and the RFID reader communicate via an RS232
interface (SECS-I).
Character structure
Data is transmitted or received in a serial bit stream of 10 bits per
character at one of the specified data rates. The standard character has one
start bit (0), 8 data bits and one stop bit (1). All bit transmissions are of the
same duration.
SECS-I performs no parity or other verification of the individual bytes.
Block transfer
protocol
The gateway uses an interpretation of SECS-I by a serial transport layer.
The following are some points to note about this implementation.
Master-Slave
The host connects to the reader. If there is a conflict, the host "gives in"
(i.e. receives before sending).
In the course of communication, the reader takes on the role of the master
and the host takes on the role of the slave.
Control characters
The four standard handshake codes used in the block transfer protocol are
displayed in the table below.
<ENQ>
0x05
Request to send
<EOT>
0x04
Ready to receive
<ACK>
0x06
Correct reception
<NAK>
0x15
Incorrect reception
