Communication
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9.4
M-Bus module MI with 2 pulse inputs
The M-Bus module enables the meter to communicate with an M-Bus center
in order to transmit measured values. In addition to a possible voltage supply
from the M-
bus connection, the “MI” module is equipped with a battery. This
powers the module processor and the pulse input, if no M-bus voltage is ap-
plied.
M-Bus
Standard
EN 1434-3; EN 13757-2, -3
Protocol
EN 60870-5
Electrical isolation
from the meter
yes
from the pulse inputs
no
Connection
strip-back length
5 mm
Connection capacity
rigid or flexible
0.25 ... 0.75 mm²
flexible with wire end ferrule
0.25 ... 0.75 mm²
Polarity
any
Voltage
50 V DC max.
Current consumption
1 M-Bus load (1.5 mA)
Addressing
primary or secondary
Baud rate
300, 1200, 2400, 4800 or 9600 baud
Interface description
see TKB3448
Pulse
Number of pulse inputs
2
pulse inputs per “MI” module
Life of the module battery
5 years of ope 1 year storage
duration;
if the M-bus voltage is applied for at
least 90% of the operating time, the
battery life increased to 10 years
Standard for pulse inputs
Class IB per EN 1434-2
Frequency
Max. 10 Hz
Pulse duration (low)
≥ 50 ms
No-pulse duration (high)
≥ 50 ms
Pulse value
0.01 liters/pulse, in steps of 10 000.00
liters/pulse,
in steps of 0.01 liters/pulse
Display and output
in m
3
, 7-digit;
acc. to parameter setting with or with-
out 1 decimal place
Polarity
yes, must be correct, if transmitter is of
type “open collector”
Electrical isolation
from the meter:
yes
from the M-bus inputs:
no
Output voltage
approx. 3.3 V
Internal resistance
approx
. 1 MΩ
Source current
approx. 3 µA
Pulse input closed (low)
Switching threshold low < 0.2 V
Resistance
< 50 kΩ
Pulse input open (high)
Switching threshold high: unconnected
collector
Resistance
≥ 6 MΩ
Connection
Strip-back length 5 mm
Connection capacity
