H1W200102 Datasheet, PDF (5/10 Pages) rfsolutions.ltd – Micro RWD H1 “Wiegand” Output Version

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The serial communication system and protocol allows for a 10ms ‘window’ every Tag polling
cycle indicated by the BUSY line being low. During this ‘window’ the host must assert the
first start bit and start transmitting data. The BUSY goes high again 10ms after the last stop
bit is received. NOTE that only one command sequence is handled at a time.
NOTE also that the acknowledge or data reply from the MicroRWD to the host can take
two seconds when a tag is brought into the RF field for the first time. This is to allow
sufficient separation of the Wiegand data frames.
Transmitted or Received data byte, 9600 baud, 8 bit, 1 stop, No parity (104µS per bit)
b0 b1 b2 b3 b4 b5 b6 b7 b8 b9
5v
1
0
TTL levels
0v
idle START
8 bit data
STOP idle
RWD tag polling cycle and serial communication BUSY protocol
RWD 5v
BUSY
0v
RWD 5v
RX
0v
RWD 5v
TX
0v
Ready to Receive
Busy
Ready to Receive
RWD cannot receive CMD or DATA
CMD/DATA
CMD/DATA
Host must Transmit CMD/DATA within 10mS of BUSY going low
DATA
Polling delay (100mS to 600mS)
(+2 seconds for first Wiegand data frame)
Wiegand data output (only first time tag in RF field)
Command Protocol
The following commands are supported. The corresponding acknowledge code should be read
back by the host and decoded to confirm that the command was received and actioned
correctly. The serial bit protocol is 9600 baud, 8 bits, 1 stop, no parity (lsb transmitted first).
The status flags returned in the Acknowledge byte are as follows:
b7 b6 b5 b4 b3 b2 b1 b0
1 1 1 1 1111
| | | | | EEPROM error (Internal EEPROM write error)
| | | | Tag OK (Tag ident code matched to list)
| | | Rx OK (Tag comms and acknowledgement OK)
| | RS232 error (Host serial comms error)
| RELAY Enabled flag
HTRC (or Antenna fault) error flag
Note that bits 6 and 7 are fixed 1’s so that an acknowledge code of D6 (Hex) would generally indicate no errors
with a matched (and authenticated) Tag present.
Note also that only the relevant flags are set after each command as indicated in the following specification.
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