AMB8426-M_8626-M_MA_EN_V2_4
Page 5 of 48
Released: Nov.2013
1 Summary
The wireless M-bus (wM-Bus) radio module AMB8426-M / AMB8626-M was designed as a
subcomponent group for the wireless reading of meters. It complies with the requirements of
EN13757-4:2011 (wireless M-bus; see [1]) and can be used where ever radio communication is
required.
The following operating modes are supported:
S1 / S1-m / S2
T1 / T2 (meter / other)
R2
C1 / C2 (meter / other)
T2 + C2 (other) combined
A serial interface (UART, optionally SPI) of which the data rate and format can be adjusted, is
available for the communication with the host system.
All transfer parameters listed in the standard EN 13757-4 (coding methods, chip rate, carrier
frequency, preamble length, etc.) can be adjusted flexibly via the user interface.
The module is suitable for use in a battery operated meter, but can also be used in a repeater or
a concentrator.
2 Communication with the Customer Application
Via the serial user interface both the transparent buffered data transfer as well as the device
configuration takes place in the so called command mode.
2.1 Transparent buffered Data Transfer
2.1.1 Wireless Transmission of Data
In this mode the user data to be transmitted is sent to the radio module via the serial interface
and is initially buffered.
The maximum number of user data bytes is selectable
APP_MAXPacketLengrh
.
A
‘Length byte’ must be placed in front of the actual payload data (see Figure 1). The length
255 (0xFF) is not allowed. The minimum length of user data is 9 bytes.
Figure 1:
Telegram format of serial interface, Block 1 is added by the module
After all data has been received, the radio transmission takes place according to the configured
wM-Bus mode of operation (see chapter 6).
