Requirements On The M-Bus Application Software - Relay MOD002 User Manual

Modems for the level converter are pre-configured for the M-Bus mode for delivery. Should
the modem be used for other data communications systems or if you are not sure whether it
has been setup for the M-Bus mode, it can be reconfigured at any time. You will need a 1:1
RS-232C interface cable for this purpose (not the cable described above and supplied!) and
a PC with a terminal program.
Configuration Steps for Modem (M-Bus at Level Converter Side)
•
Start terminal program and select COM port, any data format and baud rate for example
9600,8,N,1.
•
Enter AT<CR> (modem should detect baud rate; if no entry echo appears on the screen,
enter next command line blindly).
•
Enter AT&F<CR> (initialize modem with factory profile).
•
ATU2<CR> (user command to set M-Bus mode). Note: Both lines may be combined to
AT&FU2<CR>. The U2 command saves the set profile in both EEPROM profiles in the
modem. No more entry echoes are output by the modem after this entry (quiet mode).
This configuration has the advantage that the modem returns to the M-Bus mode if the
operating voltage is disconnected or the modem receives an ATZ command.
Modem and level converter are connected with the special serial cable. The telephone cable
(also supplied with the accessories) is then plugged into the telephone socket. The M-Bus
modem is ready for operation when the operating voltage is applied (no on/off switch!). The
bus modem can now be called from the PC modem and M-Bus data can be transmitted.

5. Requirements on the M-Bus Application Software

•
Data format:
•
Initialization of modem:
•
Dialling:
•
Hanging up:
The M-Bus baud rate is defined by the PC software by selecting the baud rate to the PC
MODEM. The baud rate can be changed online (for example from 2400 baud to 300 baud).
The permissible response time for the M-Bus meter should be increased due to the delays
on the telephone line (min. 200 ms).
M-Bus - MODEM
GmbH, Stettiner Str. 38, D-33106 Paderborn
8 data bits, even parity, 1 stop bit,
baud rate = M-Bus baud rate (300 or 2400 baud)
AT&FU1<CR>
ATDT<telephone number><CR> (voice frequency)
or ATDP<telephone number><CR> (pulse mode)
Drop the DTR line (Important, "+++" entry followed by
ATH0 is not possible)
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