14
NOTE. Using the optical button in the flow meters has the following
features:
- The button works "slowly", i.e. its touching should last more than 1 s
- The button is triggered when the finger is taken off.
1.5.5.2. RS-485 interface
RS-485 serial interface allows to read out measuring, archival, instal-
lation and diagnostic information, to modify setting parameters. RS-485
interface supports ModBus protocol (RTU ModBus and ASCII ModBus)
RS-485 interface provides cable communication in a group of several
subscribers, one of which can be a PC, with a communication line length
of up to 25 m.
At the time of release from production the network address is rec-
orded in the flow meter
– 1. Using switches SK1 and SK2 on the interface
module (see Fig.A.3), you can change the network address of the device
according to Table 6.
Table 6
Switch position
Network address
SK1
SK2
1
2
2
2
1
3
1
1
4
When both switches are set to position 2 on the interface, you can
set any network address of the device (from 1 to 255).
The RS-485 baud rate and other communication parameters are set
programmatically.
1.5.5.3. M-Bus interface
The M-Bus interface complies with EN 13757. The interface allows
the readout of measured data, such as: current flow rate, accumulated
direct, reverse and total volumes, operating time, as well as the presence
of emergencies under the numbers 1 ... 3 (see Table 7).
By default, the flow meter has a network address of 1 and an ex-
change rate of 2400 baud. The interface is connected via two wires, the
polarity of the connection is not important. The M-Bus interface baud rate
is set programmatically.
WARNING:
Power supply of the flow meter and M-Bus modem from
one power source is prohibited.
1.5.5.4. Wireless M-Bus interface
The Wireless M-Bus interface complies with EN 13757-4. The inter-
face allows the transmission of measured and archived data to a receiver
(WM-Bus dongle interface box, hub, etc.).
T1 mode is implemented in the protocol: the flow meter works only
for transmission without requests from the data acquisition device. The
transmission period is 16 seconds and the carrier frequency is 868 MHz.
Each parcel transmits a Wireless M-Bus identifier, which includes the
serial number of the flow meter, which determines which metering device
(from which consumer/subscriber) received the data.
