Protocol FlexiPOS - Vectron Systems AG

Axel Ilenburg, December, 06th 2000
Basics
V
Protocol FlexiPOS
This document describes the FlexiPOS protocol.
Software / Communication protocol
Basics
• No polling – every device sends the data as soon as they are available.
• No hardware handshake. The protocol is interactive (the next message is not sent
until the previous message was acknowledged) – so an overflow of the input buffers
should never occur (as long as the input buffer is as large or larger than the
longest message).
• The ANSI (= Windows) character set is used.
• The protocol is non-transparent, i.e. the data fields may not contain any control
characters (characters below 0x20).
• The LRC is calculated by XOR over the data (not including STX).
• After a NAK the transmission is repeated up to 2 time (total of 3 tries).
• Version check: The protocol should have two version numbers, main and sub version:
• Main version: Changes if the protocol is no longer compatible.
• Sub version: Changes if new features are added but the protocol is still compatible.
• Sometimes several data fields have to be transmitted at once (e.g. display content
and valve timing) – to chain data fields in a message an ETB-character (end of
transmission block) is used followed by the next block (LRC and STX are not sent).
Sample: “STX, Data1, LRC, ETX” and “STX, Data2, LRC, ETX” are combined to
“STX, Data1, ETB, Data2, LRC, ETX”. If the block is not valid (the answer is NAK)
all fields are ignored. In case more than one of the message parts needs an answer
other than ACK the sequence should be ignored and answered with NAK.
Control characters
STX 0x02
ETX 0x03
ACK 0x06
Protocol FlexiPOS Jul, 08 1999 1/1

NAK 0x15
Messages
• Login (from POS):
• Purpose:
• Activates the external device
• Contents:
• Nothing
• Format:
Possible answers:
STX = 1 byte
“VL” = 2 bytes
ETX = 1 byte
LRC = 1 byte
Login Acknowledge = Normal answer (see below)
NAK = Message invalid (format or LRC)
• Login acknowledge (to POS):
• Purpose:
• Acknowledges the login
• Transmits the version numbers
• Contents:
• Main version
• Sub version
• Format:
STX = 1 byte
“VA” = 2 bytes
Main version = 2 byte (‘00’ to ’99’)
Sub version = 2 byte (‘00’ to ’99’)
ETX = 1 byte
LRC = 1 byte
• Possible answers:
ACK = OK
NAK = Message invalid (format or LRC)
At now the version numbers aren’t checked if they are valid.
• Reset (from POS):
• Purpose:
• Reset after error conditions to set system into a well defined state (Clear
display, reset input mode etc.)
• Contents:
Protocol FlexiPOS Jul, 08 1999 2/2

• Nothing
• Format:
STX = 1 byte
“VR” = 2 bytes
ETX = 1 byte
LRC = 1 byte
• Possible answers:
• Logout (from POS)
• Purpose:
ACK = OK
NAK = Message invalid (format or LRC)
• Deactivates the external device in situations where the POS can not process
an information (e.g. in programming mode)
• Contents:
• Nothing
• Format:
STX = 1 byte
“VO” = 2 bytes
ETX = 1 byte
LRC = 1 byte
• Possible answers:
ACK = OK
NAK = Message invalid (format or LRC)
• Display update (from POS)
• Purpose:
• Transmits display contents
• Contents:
• Delete mode:
• 0: first numeric key pressed erases whole display
• 1: first numeric key pressed erases bottom line only
• Data length (for 2 lines)
• Data (for 2 lines)
• Format:
STX = 1 byte
“VD” = 2 bytes
Delete mode = 1 byte
Data len line 1 = 2 bytes
Data line 1 = ??? bytes
Data len line 2 = 2 bytes
Data line 2 = ??? bytes
ETX = 1 byte
LRC = 1 byte
Protocol FlexiPOS Jul, 08 1999 3/3

• Possible answers:
• Beep (from POS)
• Purpose:
ACK = OK
NAK = Message invalid (format or LRC)
• Operate the beeper
• Contents:
• Type (e.g. Short, Long, Error etc.)
• Format:
STX = 1 byte
“VB” = 2 bytes
Type = 1 byte (‘0’ to ’9’)
ETX = 1 byte
LRC = 1 byte
• Possible answers:
ACK = OK
NAK = Message invalid (format or LRC)
• Set input mode (from POS)
• Purpose:
• Selects an input mode.
This command is send after the POS gets the “Login acknowledge” message.
• Contents:
• Mode number:
• Format:
• 0: undefined
• 1: input prohibited
• 2: numeric (bottom line used, 16 characters max.)
• 3: numeric with asterisks displayed (bottom line used, 16 characters
max.)
• 4: CL only (to force the user to confirm a severe error message with CL)
• 5: reserved for alphanumeric etc. (could work similar to alphanumeric input
on mobile phones)
STX = 1 byte
“VM” = 2 bytes
Input mode = 2 bytes (‘00’ to ’99’)
ETX = 1 byte
LRC = 1 byte
• Possible answers:
ACK = OK
NAK = Message invalid (format or LRC)
Protocol FlexiPOS Jul, 08 1999 4/4

• Set status mode (from POS)
• Purpose:
• Selects mode for clerk lock and coffee machine
This command is send after the POS gets the “Login acknowledge” message.
• Contents:
• Coffee machine mode:
• 0: Normal
• 1: Binary
• Clerk lock mode:
• Format:
• 0: WITH detection of key removal
• 1: WITHOUT detection of key removal
STX = 1 byte
“VC” = 2 bytes
Coffee mach. Mode = 1 byte (‘0’ or ’1’)
Clerk lock mode = 1 byte (‘0’ or ’1’)
ETX = 1 byte
LRC = 1 byte
• Possible answers:
ACK = OK
NAK = Message invalid (format or LRC)
• Set authorisation line for coffee machine (from POS)
• Purpose:
• Selects mode for clerk lock and coffee machine
This command is send after the POS gets a “Input event” message for clerk
sign in/off.
• Contents:
• Line status:
• Format:
• 0: Offline
• 1: Online
STX = 1 byte
“VA” = 2 bytes
Line status = 1 byte (‘0’ or ’1’)
ETX = 1 byte
LRC = 1 byte
• Possible answers:
ACK = OK
NAK = Message invalid (format or LRC)
Protocol FlexiPOS Jul, 08 1999 5/5

• Input event (to POS)
• Purpose:
• Transmits events like functions key, clerk lock events etc. to the POS
• Contents:
• Function key:
• PLU 1
• Guest Check 2
• Clerk 3
• Payment 4
• Multiplier 5
• CL 6
• Quantity A 7
• Quantity B 8
• Quantity C 9
• Right arrow 10
• Dallas sign in 51
• Dallas sign out 52
• Other clerk key 53 and higher
• Contents of the input buffer or clerk number (in case of the Dallas key full
serial number including the family code as hex (e.g. “0600000010BAB7”).
• Format:
STX = 1 byte
“VI” = 2 bytes
Event = 2 bytes (‘00’ to ’99’)
Buffer bytes used = 2 bytes (‘00’ to ‘32’)
Buffer = 0 to 32 bytes
ETX = 1 byte
LRC = 1 byte
• Possible answers:
ACK = OK
NAK = Message invalid (format or LRC)
• Product request (to POS)
• Purpose:
• Requests if it is allowed to get a certain product
• Contents:
• Device number (CodeCap, Pourer or Coffee machine):
• 0: undefined
• 1: Pourer
• 2: CodeCap
• 3: Coffee machine
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Every external device except the BarMaster has to use the device number 2.
• Product number
• Format:
STX = 1 byte
“VQ” = 2 bytes
Device = 1 byte (“0” to “9”)
Product no. = 5 bytes (“00000” to “99999”)
ETX = 1 byte
LRC = 1 byte
• Possible answers:
Product acknowledge = Normal answer (see below)
NAK = Message invalid (format or LRC)
• Product acknowledge (from POS)
• Purpose:
• Answer to a product request
• Contents:
• Device number
• Product number
• Status:
• Format:
• 0: not allowed
• > 0 for Cap: allowed
• > 0 for Pourer: opening time
STX = 1 byte
“VP” = 2 bytes
Device = 1 byte (‘0’ to ‘9’)
Product number = 5 bytes (‘00001’ to ‘99999’)
Status/Time = 4 bytes (‘0000’ to ‘9999’)
ETX = 1 byte
LRC = 1 byte
• Possible answers:
ACK = OK
NAK = Message invalid (format or LRC)
• Product registration (to POS)
• Purpose:
• Confirms that the product was taken
• Contents:
• Device number
• Product number
• Format:
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STX = 1 byte
“VG” = 2 bytes
Device = 1 byte (‘0’ to ‘9’)
Product number = 5 bytes (‘00001’ to ‘99999’)
ETX = 1 byte
LRC = 1 byte
• Possible answers:
Example
ACK = OK
NAK = Message invalid (format or LRC)
Sample sequence (with several error situations):
POS: Login
Ext. Dev.: Login acknowledge
POS: Display update; Set input mode (numeric); Set status mode
Ext. Dev.: Input event: Dallas serial number
POS: Display update;
Ext. Dev.: Input event: Table number
POS: Display update: error message “invalid table number”; Beep
Ext. Dev.: Input event: Table number
POS: Display update: Table name and balance
Ext. Dev.: Product request: Pourer, PLU 123
POS: Display update: “Invalid PLU”; Product acknowledge: not allowed;
Beep
Ext. Dev.: Product request: Pourer, PLU 100
POS: Display update: PLU name, available sizes; Product acknowledge:
timing value
Ext. Dev.: Input event: Soft key for other size
POS: Display update: PLU name, available sizes; Product acknowledge:
timing value
Ext. Dev.: Product registration
Ext. Dev.: Input event: Table key
POS: Display update: Table name and balance
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