Rh eo n i k M esst ech n i k
RE V . L O ct o b er 2014
.
RHEONIK Coriolis Flowmeter
Operation Manual RHE 07, 08, 11
Page
20
2.1.3.6.2. Serial communication
The RHE remote electronic unit supports either RS422 / 485 full duplex (4 wire sys-
tem) interfaces (RS232 only as special option).
TTL level serial can also be used. Transmission baudrate can be set in baudrate menu
(300, 600, 1200, 2400, 4800, 9600, 19200 bits/second).
The serial interface can be used in a bus (4 wire). For this purpose each remote unite has
to be addressed separately.
For RS422/485 connect communications wiring pairs to the TX+/TX- terminals and to the
RX+ /RX- terminals (see attached wiring diagram).
Standard character format is:
7 bit ASCII, 1 start bit, 1 stop bit, parity bit EVEN.
For network communication each transmitter RHE has to have its own
network address
from A to Z
available in menu
Setup I/O
/
Dig
in menu point
Network Adr
.
Basic Command Format:
Commands are sent by the computer to the transmitter. The message protocol uses only
ASCII characters as follows:
- Command header:
<7FH><7FH><#>[<address>]
Address is any character ´
A
´ to ´
Z
´. If the transmitter has no address, no address
character needs to be transmitted. If ´$´ is transmitted as an address, this character is
valid as an address. All transmitters in a network will respond to this adress.
- Request instructions:
If any of the below listed request instructions are transmitted after the command head,
the transmitter will send back the requested information.
Request for
command
RHE reply
example
________________________________________________________________
flow rate
f?
f= ...
f=_1.987kg/min
totalizer
q?
q= ...
q=____413.4lb
temperature
t?
t= ...
t=-_12.4C
density*)
d?
d= ...
d=16.435lb/gal
totalizer
(non resetable)
m?
m= ...
m=___36782kg
analog input
a?
a= ...
a=_10.16bar
error message **)
e?
e= ...
e=3FH
warning **)
w?
w= ...
w=5
*) Only with option density measurement.
**) error and warning code in HEX
