DNF Controls ST420-CP - Manual (Page 5)

ST420 Control Panel 5 5
5. PROTOCOL DESCRIPTION
a. COMMUNICATIONS FORMAT
Baud Rate
38.4K
Parity ODD
Data Bits 8
Stop Bits 1
b. COMMANDS
Command Format: STX + BC + CMD + DATA + CHECKSUM
STX =
0x02
BC = Byte Count (8 bits) (Byte Count includes all bytes between BC and Checksum,
exclusively.)
CMD = 1 byte
DATA = Data bytes, number of bytes dependent upon CMD
CHECKSUM = Simple 8 bit sum of ALL preceding bytes
ACK =
STX + 01 + 0x04 + Checksum
NAK = STX + 01 + 0x05 + Checksum
ST420 External Control System
Key Press/Release:
STX+ BC + ’K’+ KeyData0 + KeyData1 + … + KeyData5 + Checksum ÎÎÎ
BC: Byte count = 7
KeyData0 … KeyData5 – state of the keyboard (see Keyboard Decode Table)
ÍÍÍÍÍÍ No response required
NOTE- Key Press/Release status is sent on every key change. If all KeyData = 0, then all keys
have been released.
Key Press/Release Status:
ÍÍÍÍÍÍ STX + 01 + ‘K’ + Checksum
STX+ BC + ’K’+ KeyData0 + KeyData1 + … + KeyData5 + Checksum ÎÎÎ
BC: Byte count = 7
KeyData0 … KeyData5 – state of the keyboard (see Keyboard Decode Table
Key LED Control:
ÍÍÍÍÍÍ STX + BC + ‘L’ + Led Data1 + Led Data2 + Checksum
BC: Byte count = 3
Data1= LED1 (Lsb) to LED8 (Msb)
Data2= LED9 (Lsb) to LED16 (Msb)
STX + 01 + ACK + Checksum ÎÎÎÎÎÎÎÎ