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Protocol Constants

All constants live in alphasign.protocol and are re-exported from alphasign.

CommandCode

One-byte command codes (Table 6 of the M-Protocol spec).

Member Byte Description
WRITE_TEXT A Write TEXT file
READ_TEXT B Read TEXT file
WRITE_SPECIAL E Write SPECIAL FUNCTION
READ_SPECIAL F Read SPECIAL FUNCTION
WRITE_STRING G Write STRING file
READ_STRING H Read STRING file
WRITE_SMALL_DOTS I Write SMALL DOTS picture
READ_SMALL_DOTS J Read SMALL DOTS picture
WRITE_RGB_DOTS K Write RGB DOTS picture
READ_RGB_DOTS L Read RGB DOTS picture
WRITE_LARGE_DOTS M Write LARGE DOTS picture
READ_LARGE_DOTS N Read LARGE DOTS picture
WRITE_BULLETIN O Write AlphaVision Bulletin

DisplayMode

Text transition / display modes.

Member Code Description
ROTATE a Right-to-left scroll
HOLD b Stationary
FLASH c Stationary, flashing
ROLL_UP e Previous message pushed up
ROLL_DOWN f Previous message pushed down
ROLL_LEFT g Previous message pushed left
ROLL_RIGHT h Previous message pushed right
WIPE_UP i Wipe from bottom to top
WIPE_DOWN j Wipe from top to bottom
WIPE_LEFT k Wipe from right to left
WIPE_RIGHT l Wipe from left to right
SCROLL m Push bottom line to top
SPECIAL n Special mode (requires SpecialMode)
AUTOMODE o Automatic mode selection
ROLL_IN p Previous pushed toward centre
ROLL_OUT q Previous pushed outward
WIPE_IN r Wipe inward
WIPE_OUT s Wipe outward
COMPRESSED_ROTATE t Compressed right-to-left scroll
EXPLODE u Flies apart from centre (Alpha 3.0+)
CLOCK v Clockwise wipe (Alpha 3.0+)

SpecialMode

Specifiers for DisplayMode.SPECIAL.

Member Code Effect
TWINKLE 0 Twinkling
SPARKLE 1 Sparkle over previous
SNOW 2 Snow
INTERLOCK 3 Interlock
SWITCH 4 Alternating character switch
SPRAY 5 Spray right-to-left
STARBURST 6 Starburst explosions
WELCOME 7 Welcome script animation
SLOT_MACHINE 8 Slot machine
NEWS_FLASH 9 Newsflash animation
TRUMPET A Trumpet animation
CYCLE_COLORS C Colour cycle
THANK_YOU S Thank You animation
NO_SMOKING U No smoking animation
DONT_DRINK_DRIVE V Don't drink and drive
RUNNING_ANIMAL W Running animal / fish
FIREWORKS X Fireworks
TURBOCAR Y Turbo car / balloons
CHERRY_BOMB Z Cherry bomb

DisplayPosition

Vertical/horizontal text position.

Member Byte Description
MIDDLE_LINE 0x20 Centred vertically
FILL 0x26 Fill all lines
TOP_LINE 0x30 Top (all lines – 1)
MIDDLE 0x31 Middle (default)
BOTTOM_LINE 0x32 Bottom
LEFT 0x3C Left (Alpha 3.0+)
RIGHT 0x3E Right (Alpha 3.0+)

Color

Embedded colour control sequences.

RED, GREEN, AMBER, DIM_RED, DIM_GREEN, BROWN, ORANGE, YELLOW, RAINBOW1, RAINBOW2, MIX, AUTO.

PixelColor

Single-character pixel codes for DOTS pictures.

OFF (0), RED (1), GREEN (2), AMBER (3), DIM_RED (4), DIM_GREEN (5), BROWN (6), ORANGE (7), YELLOW (8).

Font

Font selection control sequences.

FIVE_HIGH_STD, FIVE_STROKE, SEVEN_HIGH_STD, SEVEN_STROKE, SEVEN_HIGH_FANCY, TEN_HIGH_STD, SEVEN_SHADOW, FULL_HEIGHT_FANCY, FULL_HEIGHT_STD, SEVEN_SHADOW_FANCY, FIVE_WIDE, SEVEN_WIDE, SEVEN_FANCY_WIDE, WIDE_STROKE_FIVE, FIVE_HIGH_CUSTOM, SEVEN_HIGH_CUSTOM, TEN_HIGH_CUSTOM, FIFTEEN_HIGH_CUSTOM.

Other Enums

Enum Members
DayOfWeek SUNDAY–SATURDAY
TimeFormat STANDARD (12h), MILITARY (24h)
FileType TEXT, STRING, DOTS
FileProtection UNLOCKED, LOCKED
DotsColorDepth MONO, THREE_COLOR, EIGHT_COLOR
BulletinPosition TOP, BOTTOM
BulletinJustification LEFT, CENTER, RIGHT
SpecialFunction All E/F sub-function codes
TypeCode Sign type codes

Framing Constants

from alphasign.protocol import SYNC, SOH, STX, ETX, EOT, ESC, DELAY, ACK, NAK
Constant Value Meaning
SYNC b"\x00" × 5 Sync / baud-rate establishment
SOH b"\x01" Start of Header
STX b"\x02" Start of Text
ETX b"\x03" End of Text
EOT b"\x04" End of Transmission
ESC b"\x1B" Escape (precedes display position)
DELAY b"\xFF" 100 ms timing marker (never transmitted)
ACK 0x06 Acknowledgement (int)
NAK 0x15 Negative acknowledgement (int)