User's Manual

Hi-G-Tek Ltd. Microelectronics & Asset Tracking Technology
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6
RS 485/232 Communication Protocol
There are 2 types of commands: SHORT COMMANDS and LONG
COMMANDS.
Short Commands: These are commands that are relevant to
internal tasks at the reader level.
Long Commands: These commands involve sessions with seals.
The READER will respond to commands generated by the LSC
within T seconds.
RLSC
For short commands, response time should be: T = 50 msec.
RLSC
For long commands, the LSC should return to retrieve the results
after T with the appropriate GET RESULTS command.
session
T is a derivative of the type of command executed to the seals.
session
Acknowledge can be positive or negative.
If the LSC detects a problem, Acknowledge will be negative.
The READERS are designed to work in cycles. Following an
internal or external trigger, a READER SESSION is generated.
This is a full communication cycle going back and forth between
a READER and the tags located in the READER's receiving zone.
The LSC operates differently The READERs are scanned on a
different time line, using the same frequency as that of the
READER's cycles or greater.
This protocol supports RS-485 and RS-232 communication
fashions. When working with the LSC using RS-232 communication
opposite only one device, address fields should be set to 0xFFFF.
When using RS-485 communication in broadcast situations, the
address field should be set to 0x0000.