Contrive Quad - Fieldbus Remote Control and Communication; Fieldbus Communication Protocol and Timing

© 2000 CONTRIVE • B1401.EN 0211 11 www.contrive.it
FIELDBUS REMOTE CONTROL
TraxBus using busbars or single wire lines
Ref. to TraxInterface
3
literature [B1300] for wiring details
Complete remote control and supervision is possible
through built-in serial communication interface using
proprietary fieldbus, designed for reliable operation in
harsh industrial environments with simplified wiring.
Communication protocol could be easily implemented
into any programmable controller for great efficiency
and low cost. Ready to use gateways are available to
convert TraxBus into standard industry fieldbus systems.
Typical communication time at different baud rates are
summarized below.
Since any supervisor takes some time for internal
processing, the real performance of the fieldbus must be
computed adding such delay.
POLLING TIME FOR 1 BURNER
4800 9600 19200 38400
COMMAND 15 ms 8 ms 4 ms 2 ms
ANSWER 15 ms 8 ms 4 ms 2 ms
OVERALL 30 ms 16 ms 8 ms 4 ms
POLLING TIME FOR 10 BURNERS
4800 9600 19200 38400
COMMAND 150 ms 80 ms 40 ms 20 ms
ANSWER 150ms 80 ms 40 ms 20 ms
OVERALL 300 ms 160 ms 80 ms 40 ms
POLLING TIME FOR 100 BURNERS
4800 9600 19200 38400
COMMAND 1,5 s 800 ms 400 ms 200 ms
ANSWER 1,5 s 800 ms 400 ms 200 ms
OVERALL 3,0 s 1600 ms 800 ms 400 ms
Messages to/from remote host supervisor must be ASCII
characters, 8 bits, no parity, 1 or 2 stop bits.
COMMAND FROM SUPERVISOR TO PERIPHERALS
Commands are issued to peripherals within a single
string terminated with Carriage Return.
< S N C KK <Cr> < Preamble (from master)
S Segment, Zone identifier
N Node, Unit identifier
C Command
KK Checksum
<Cr> Carriage return
STATUS FROM PERIPHERALS TO SUPERVISOR
Peripherals will acknowledge all valid command received
from supervisor:
> S N T KK <Cr> > Preamble (to master)
S Segment, Zone identifier
N Node, Unit identifier
T Status
KK Checksum
<Cr> Carriage return
S and N can be any alphanumeric character and must match the settings of the peripheral to be addressed.
Since Quad+Flair valid settings are within the range 01…FD, the maximum addressable units on a single bus are 252.
The special character * (star) can be used like wild card to send broadcast command: a star character instead of S will
address all existing nodes, a star character instead of N will address the whole segment, two star characters will
address all the connected units. Of course no acknowledge answer will be sent back after broadcast commands.