ib technology

6

Message

Command to return product and firmware identifier string to host.

B7

B0

Command:

0 1 1 1 1 0 1 0

(ASCII “z”, 0x7A)

Reply:

“a IDE RWD H2 (SECx V1.xx) DD/MM/YY” 0x00

Returned string identifies author, product descriptor, project name, firmware version no.

and date of last software change. Note that the string is always NULL terminated. The

string begins with a unique lower case character that can be used to identify a particular

version of Micro RWD.

NOTE:

1) The serial communications uses hardware handshaking to inhibit the host from

sending the Micro RWD commands while Tag interrogation is in progress.

2) Following the Read Tag command, if an error flag has been set in the

Acknowledge code then there will be NO following data.

3) The serial communications 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.

4) Only one command sequence is handled at a time.

Program EEPROM

The Micro RWD has some internal EEPROM for storing system parameters such as

passwords and authorised identity codes. This command sequence allows individual

bytes of the EEPROM to be programmed with new data. Note that due to the

fundamental nature of these system parameters, incorrect data may render the system

temporarily inoperable.

B7

B0

Command:

0 1 0 1 0 0 0 0

(ASCII “P”, 0x50)

Argument1:

N N N N N N N N

(N = EEPROM memory location 0- 255)

Argument2:

D D D D D D D D

(D = data to write to EEPROM)

Acknowledge:

1 1 X F X X X F

(F = Status flags)