Siemens SIMATIC S7-200 System Manual page 244

S7-200 Programmable Controller System Manual
Configuring a Remote Modem
The remote modem is the modem that is
connected to the S7-200. If the remote
modem is an EM 241 Modem module,
no configuration is required. If you are
connecting to a stand-alone modem or
cell modem, you must configure the
Modem
connection.
Expansion
Wizard
The Modem Expansion wizard
configures the remote modem which is
connected to the S7-200 CPU. Special
modem configurations are required in
order to properly communicate with the
RS-485 half duplex port of the S7-200
CPU. Simply select the type of modem,
and enter the information as prompted and enter the information as prompted
by the wizard. For more information,
refer to the online help.
Configuring a PPI Multi-Master Cable to Work with a Remote Modem
The RS-232 PPI Multi-Master cable
provides the ability to send modem AT
command strings upon power-up of the
cable. Please note that this
configuration is only required if the
default modem settings must be
changed. See Figure 7-27.
Modem commands can be specified in
the General commands. The auto
answer command will be the only default
setting.
Cell phone authorization commands and
PIN numbers can be specified in the Cell
Phone Authorization field, for example
+CPIN=1234.
Each command string will be sent
separately to the modem. Each string will
be preceded with the AT modem
attention command.
These commands will be initialized within Th
the cable by selecting the Program/Test
button.
Please note that the bitmap will depict the recommended switch settings depending upon the
selected parameters.
While configuring the RS-232/PPI Multi-Master cable with STEP 7--Micro/WIN, you must connect
the RS-485 connector to an S7-200 CPU. This is the source of the 24V power required for the
cable to operate. Be sure to supply power to the S7-200 CPU.
After exiting the STEP 7--Micro/WIN configuration of the RS-232/PPI Multi-Master cable,
disconnect the cable from the PC and connect it to the modem. Power cycle both the modem and
the cable. You are now ready to use the cable for remote operation in a PPI multi-master network.
Tip
Your modem must be at the factory default settings for use with a PPI Multi-Master cable.
230
d ill b i iti li d ithi
Figure 7-26 Modem Expansion Wizard
Figure 7-27 Modem Expansion Wizard - - Sending Modem
Commands