Matrix Orbital LK204-7T-1U - Manual (Page 18)

18
6 Commands
6.1 Communication
1.1 Change
Baud Rate Dec
Hex
ASCII 254 57
FE 39
■ 9
Speed
Speed
Speed v5.0
Immediately changes the baud rate. Not available in I2C. Baud rate can be temporarily forced to 19200 by a
manual override.
Speed Byte Valid settings shown below.
Table 11: Accepted Baud Rate Values
Rate 1200 2400 4800 9600 19200 28800 38400 57600 * 76800 * 115200
Speed 83 41 207 103 51 34 25 16 12 8
*Note:
Baud rates 76800 and 115200 added after firmware revision 5.0 was released as per PCN 2006-08-2
1.2 Change I
2
C
Slave Address
Dec
Hex
ASCII 254 51
FE 33
■ 3
Address
Address
Address v5.0
Immediately changes the I
2
C write address. Only even values are permitted as the next odd address will become
the read address. Default is 80.
Address Byte Even value.
1.3 Transmission
Protocol Select Dec
Hex
ASCII 254 160
FE A0
■ á
Protocol
Protocol
Protocol v5.0
Selects the protocol used for data transmission from the display. Data transmission to the display is not affected.
Must be set to the protocol in use to receive data correctly.
Protocol Byte 1 for Serial (RS232/RS422/TTL/USB) or 0 for I
2
C.
1.4 Set a Non-Standard
Baud Rate Dec
Hex
ASCII 254 164
FE A4
■ ñ
Speed
Speed
Speed v5.0
Immediately changes the baud rate to a non-standard value. Speed must be a whole number between 977 and
153800. Due to rounding, error increases with baud rate, actual baud must be within 3% of desired baud to ensure
accurate communication. Not available in I2C. Can be temporarily forced to 19200 by a manual override.
Speed Word Calculations shown below, standard crystal speed is 16MHz.
( )
Equation 1: Speed Byte Calculation
( ( ))
Equation 2: Actual Baud Rate Calculation
| |
Equation 3: Baud Rate Error Calculation