Instructions for Assembly and Operating
SONIX 30D
THE SERIES RS485 OUTPUT
14
Protocol
description
Electrical
connections
The MODBUS RTU protocol of series transmission is compliant with the
current specification available at
www.modbus.org
Transmission speeds:
1200, 2400, 4800 or 9600 B/s. Addresses of the devices: 1 ...255.
Character format:
-1 start bit
-8 data bits
-1 parity control bit (programmable: Odd, Even, None)
-1 stop bit (or 2 stop bits when programmed to None).
Two functions are available:
03 or 04 – reading of the content of the flowmeter’s register group
06 – recording data in the flowmeter register (register nr 31 only)
Examples
of frames for the device of the 02
H
address
1. Reading of 2 registers beginning from register no 10 of the following
content:
register no 10: 057F
H
register no 11: 9D1A
H
Order: 02,03,00,09,00,02,14,3A
Response: 02,03,04,05,7F,9D,1A,11,7C
2. Setting to zero and starting the temporary volume counter:
Order: 02,06,00,1E,00,01,28,3F
Response: 02,06,00,1E,00,01,28,3F
3. Stopping the temporary volume counter:
Order: 02,06,00,1E,00,00,E9,FF
Response: 02,06,00,1E,00,00,E9,FF
The applied isolated interface is compliant with the EIA RS-485 standard. The
transmission line must be connected in accordance with labels on the printed
plate: R
A
– higher potential, R
B
– lower potential. In the case of severe
electrical interferences or if the length of the cables exceed 300m, paired
twisted 120Ω cable cat.4 wave resistance should be used.
If the flowmeter is located at the end of a transmission line exceeding 300m,
line termination should be initiated by attaching the 2 jumpers (next to the
fuse on the printed plate). Simultaneously with the termination, the line is also
polarized with the approx 2.5V voltage. (see electrical connections of the
flowmeter). The flowmeter is supplied with jumpers attached.
