AKA 245 can act as connecting link between DANBUSS and a modem.
(DANFOSS can provide information about other modem types that can be used with the gateway)
By connecting the supply to the modem via a relay switch (DO 1) on the gateway, the gateway will
be able to reset the modem. At the same time the modem will be switched on, when the gateway is
switched on. This ensures that the modem start will always be controlled.
Read the section “Connections”.
It is possible for the gateway to use commands for control ling the connec ted modem. These
commands are in the form of an initialisa tion string transmitted to the modem when it is switched on.
From the factory a modem gateway contains the following AT command string:
AT Z < CR > AT E1 SO = 2 &D2 V1
The command has the following meaning:
AT Attention
sequence
Z
Reset modem to power-up status
E1 Echo
on
V1
Verbose result codes(e.g.”CONNECT 1200" instead of “4”).
&D2
HW mode for on hook via DTR
S0=2
Auto answer ON, answer after 2 rings
The initialisation command string can be changed by means of system software type AKM.
E0, V0, S0=0, S0=0, &D0, &D1 and &D3 must not be contained in the command string.
For further information about these commands, please refer to your modem manual.
A number of modem codes can be keyed in together with a telephone number.
These modem codes attach to a specifi c telephone number and are sent on to the modem together
with the telephone number.
The following codes can be keyed and attached to a telephone number in the router table:
P:
Pulse dialling. Used in old telephone exchanges and private switching systems.
T:
Tone dialling. Used in new telephone exchanges.
W:
Wait for ringback tone (dial tone)
, :
2-second pause
%n:
Modifi es the calling speed for this particular call
* :
Special character for private switching system
# :
Special character for private switching system
For further information about these commands and codes, see the modem manual.
Call-back function
The function can be used for service and transmission of log data via the telephone network.
The call-back function is selected from the AKM programme and is essential for all systems from which
service or log data are collected.
The function sees to it that the gateway will return the call to the AKM programme, and hence pay for
the transmission time.
Procedure
The AKM programme calls the master gateway and starts the call-back function. The master gateway
then checks if the AKM programme’s system address is found in the router table.
15 seconds later the master gateway establishes a telephone connection to the AKM programme. If
the connection is not established at the fi rst try, two more attempts will be made at 5-minute intervals.
When the master gateway has established the telephone connection
the AKM programme will take
over.
An automatic log transmission is carried out in this way:
Based on the individual log defi nitions, the AKM programme knows how often it has to collect data
from a system. The AKM programme starts the procedure, and when the connection has been estab-
lished, the collection will commence.
If the master gateway does not manage to establish a telephone connection, the AKM programme will
call the master gateway again, and collection will then be started immediately.
Modem connection
TCP/IP server connection
If data communication is to take place via a LAN network (TCP/IP) the gateway can be connected to a
server.
Principle, connection and settings are described in the installation instructions for AKM.
Literature No. RI8B.P--.
AKA
245
Manual RS8DT102 © Danfoss 09/2004
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