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During M-Bus communication with an end instrument the other interfaces (push-button, optical interface) of this
instrument cannot be used.
9.4 Radio interface wireless M-Bus EN 13757-3, EN 13757-4 (optional)
The radio interface is for the transmission of meter data (absolute values).
General information about the radio interface
Installation of radio components between or behind heating pipes, or the presence of other bulky obstacles directly
over or in front of the housing must be avoided.
The transmission quality (range, telegram processing) of radio components can be negatively influenced by
instruments or equipment with electromagnetic emissions, such as telephones (particularly LTE mobile radio
standard), Wi-Fi routers, baby monitors, remote control units, electric motors, etc.
In addition, the construction of the building has a strong influence on the transmission range and coverage.
Furthermore, when using installation boxes (substations) they must be equipped with non-metallic covers or doors.
The factory-setting of the clock in the meter is standard (winter) Central European Time (GMT +1). There is no
automatic changeover to daylight savings (summer) time.
The radio function is deactivated upon delivery (factory-setting). See section 9.4.3 “Activation of the radio
interface”.
9.4.1 Technical data radio
wireless M-Bus based on EN 13757-3
- Short telegram in conformity to AMR (OMS-Spec_Vol2_Primary_v301): energy
(heat/cooling energy, pulse input 1, pulse input 2), total volume, flow, power,
information message, return flow temperature, temperature difference
- Long telegram for walk-by read-out: energy (heat/cooling energy, pulse input 1,
pulse input 2), total volume, information message, 15 monthly values
AES: Advanced Encryption Standard; key length: 128 bits
9.4.2 Radio configuration*
Factory settings
(Battery lifetime, estimated: 6 + 1 years)
00:00 – 24:00; any time period in the day
120 seconds - 240 minutes
120 seconds (heat meters)
Monday – Sunday (any weekday)
1 – 4 (4: uninterrupted, incl. a possible 5
th
week)
1 – 4 (4: uninterrupted, incl. a possible 5
th
week)
01.01 - 31.12. (day.month)
- Not encrypted
- Encrypted:
- Engelmann Master Key
- random key per instrument
- activated/not activated
Master Key; not activated
- Short telegram AMR (OMS-
Spec_Vol2_Primary_v301)
- Long telegram walk-by
*Factory settings may vary from the above.