DNF Controls ST400-CP - Manual (Page 9)

ST400-CP User Manual Page 9 of 19
4. POWER UP DEFAULTS
The ST400 powers up in the following default state:
The LCD display is blank.
All LEDs are off.
The wheel is set to OFF mode.
The ST400 is ready to receive commands from ECS.
5. PROTOCOL DESCRIPTION
a. COMMUNICATIONS FORMAT
Baud Rate 38.4K
Parity ODD
Data Bits 8
Start Bit 1
Stop Bit 1
b. COMMANDS
Command Format: STX + BC + CMD + DATA + CHECKSUM
STX =
0x02
BC = Byte Count, 1 byte
Byte Count includes all data bytes between BC and Checksum, exclusively.
CMD = 1 byte
DATA = Data bytes, command specific
CHECKSUM = Simple 8 bit sum of ALL preceding bytes (including STX)
ACK =
STX + 01 + 0x04 + Checksum
NAK = STX + 01 + 0x05 + Checksum
ST400 External Control System
Key Change Command:
STX+ BC + ’K’+ KeyChange0 + KeyChange1 + … + KeyChange5 + KeyData0 + KeyData1 +
… + KeyData5 + ChecksumÆ Æ
BC: Byte count = 13
KeyChange0 … KeyChange5 – bitmap of the keys that have changed their state
If a corresponding bit is set - there was a change, if a bit is cleared – no change from the
previous state. See Keyboard Decode Table for bitmap decoding
KeyData0 … KeyData5 – state of the keyboard
If a corresponding bit is set - the key is pressed, if a bit is cleared – the key is released.
See Keyboard Decode Table for bitmap decoding.
Å Å No response required
NOTE- Key Press/Release status is sent on every key change. If all KeyData = 0, then all keys
have been released.