Download P. P´ıˇsa, P. Smol´ık Department of Control Engineering

uLan Communication Protocol
for Laboratory Instruments, Home
Automation and Field Applications
P. Pı́ša, P. Smolı́k
Department of Control Engineering
Faculty of Electrical Engineering, Czech Technical University
[email protected], [email protected]
uLan Message Protocol
uLan is multi-master message oriented communication protocol which utilizes RS-485 signal
levels. Use of 9-bit character simplifies transfer of binary data. The data frame is a basic communication unit of the uLan protocol.
The frame has its destination, source node,
frame type or command, end mark and integrity check xor sum.
CHROMuLAN
FASTOP, HA
CHROMuLAN HPLC system software provides affordable solution for HPLC assay mathematical data processing and complex HPLC
instruments sets control over uLan communication network.
The Czech company Agrosoft Tábor is producer of FASTOP and FASTOS systems for
automatic batch distribution of feed to pigs
and cows.
Data frame format
DAdr
or
uL_Beg
SAdr
Com
0 to MaxBlock
of data bytes
uL_End,
uL_Arq,
uL_Prq
or
uL_Aap
XorSum
The deterministic arbitration is achieved by
timing rules for media access sequence.
Bus request and release
LAdr
delay
first
(LAdr-Adr-1) connect
mod 16 + 4
mark
delay
Adr
and 3
+1
delay
(Adr shr 2)
and 3 +1
delay
(Adr shr 4)
and 3 +1
transfer of data
release
frames beginning of bus by
with DAdr of
LAdr=Adr
first frame
or 80h
Many of todays microcontrollers implement 9bit extension in their UART (all Intel 8051
and 8096 based MCUs with UART, members
of Motorola 683xx family - 68376, Hitachi H8
microcontrollers, TI msp430 to name some of
them). Intel has developed a multi-protocol
UART i82510, which is very well suited for implementing 9-bit communication interface for
PC computers. The second example of the
chip, which is well suited for 9-bit communication, is OX16C954-PCI produced by Oxford
Semiconductors
Actual version of driver support this platforms:
• DOS
• Windows - 98/2000/XP with WDM driver
model
• Linux - 2.4.x as well as 2.6.x
The USB to uLan converter support is under
development now.
uLan software and dodumentation pages:
http://ulan.sourceforge.net/.
There is more HPLC instruments which can be
directly connected to the uLan bus.
The system takes advantage of uLan multimaster architecture, which reduce data traffic.
Wireless identification needs co-ordinate transmit and receive functions in order to avoid mutual interference. This function is done by periodic sending a broadcast message.
Control Computer
AAA−400
Amino Acid Analyzer
LCP5020
LCS5040
HPLC Pump
Autosampler
communication
programs (CS,Cu)
LCD500
UV−Vis HPLC Detector
The communication with instruments over
uLan network is realized as reading and witting device models properties. The models of
the devices connected to the uLan network are
built automatically from process variables and
properties description exported by each instrument.
Control System
Device 1
CHROMuLAN
User scripts
Control logic
Graphic
parameters and
User
acquired data IFPS interpretter Interface
Object tree browser and handler
Object tree of branches, properties
and process variables
Persistent
storage
Temp.
ULF, ULC storage
ULD files (mem)
Dev 1
model
Dev 2
model
uLan net. model
uLan API
Operating System
Linux/Windows
DOS
Control Computer
Hardware (PC)
uLan
driver
UART
chip
RS485
buffer
Local
display
keyboard
and UI
Device
function
appli−
cation
Device 2
Local display
keyboard, UI
and time program
uLan
object
interface
Device logic
and application
comunicating
over uLan objects
Process
variables and
device
uLan
para−
object
interface meters
uLan
API and
MCU
support
libraries
uLan
API and Contro−
MCU
llers
support sensors
libraries
etc.
UART
RS485
UART
RS485
more
HW
More about CROMuLAN project can found at
http://www.chromulan.org/.
database
Firebird
UPS
RS232
HND2000
Fastos 2000
High
Speed
Disk
communication
adapter uLan
USB
SKOT
Control room
Technology
uLan bus
feeding
unit 1... 62
Automatic Feeding Box
groats
distributions
identification
TIRIS
railing
control unit
mcu, IO, ...
Activity
identification
TIRIS
Power Source
12V,24V
control unit
mcu, IO, ...
The multi-master capability of uLan, very low
cost interconnection with use of an phone line
grade cable, free bus topology are reasons to
used it for Home Automation.