ib technology
Factory Reset
Command to restore Factory default EEPROM values and Stored Keys and perform hardware
Reset operation. The 0x55 0xAA parameters protect against accidental operation.
After Reset, the Red LED will flash 5 times indicating the successful loading of the Factory
default values.
B7
B0
Command:
Argument1:
Argument1:
0 1 0 0 0 1 1 0
0 1 0 1 0 1 0 1
1 0 1 0 1 0 1 0
(Ascii “F”, 0x46)
0x55
0xAA
Reset occurs after the command is processed so there is no Acknowledge byte reply.
Addition Notes for Commands
NOTE also that for the “Read Card Block” or “Card UID” command, if an error flag has been
set in the Acknowledge code then there will be NO following data.
NOTE that the serial communication uses hardware handshaking to inhibit the host from
sending the Micro RWD commands while Card communication is in progress. The serial
communication system and protocol allows for a 6ms ‘window’ every Card polling cycle
indicated by the CTS/BUSY line being low. During this ‘window’ the host must assert the
first start bit and start transmitting data. The CTS/BUSY goes high again 6ms after the last
stop bit is received. NOTE that only one command sequence is handled at a time. The period
between the CTS pulses (polling delay) can have three rates depending on whether a card is
present or not and if commands are being received by the RWD
NOTE that the commands and parameters must be sent to the RWD with no gaps otherwise
communication timeout occurs and the RWD enters the polling delay period (the command
string would then be incomplete and an RS232 error is flagged).
NOTE that the MicroRWD MF LP version performs fast polling cycles as long as there are
commands to be processed. As soon as the commands stop being sent or the gap between
sending commands is too long then timeout occurs and the polling delay increases to 100ms
(if the card is still present) or the typically longer period (as set by EEPROM parameter) if
there is no card. This is to allow repeated commands to be handled quickly such as for a
“complete card read” where repeated Read Block commands are sent to the RWD.
Commands sent infrequently will have the full polling delay between each CTS/BUSY
period.
Basic RWD Communication
For basic operation of the MicroRWD connected to a host computer, the RWD can either be
polled or communication can be triggered by an interrupt signal (Green LED output). In either
case the user would initially send the “STORE KEYS” command to load a custom security
key into the RWD memory or simply use the pre-loaded default key values.
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