Siemens SIMATIC S7-200 System Manual page 331

10. The Phone Numbers tab on the Configure CPU Data Transfers screen allows you to define
the telephone numbers for CPU-to-CPU or a CPU-to-Modbus data transfers. Click the New
Phone Number... button to add a new telephone number. Once a telephone number has
been configured it must be added to the project. Highlight the telephone number in the
Available Phone Numbers column and click the right arrow box to add the telephone
number to the current project. Once you have added the telephone number to the current
project, you can select the telephone number and add a symbolic name for this telephone
number to use in your program.
The Description and Phone Number fields are the same as described earlier for messaging.
The Password field is required if the remote device is a Modem module and password
protection has been enabled. The Password field in the local Modem module must be set to
the password of the remote Modem module. The local Modem module supplies this
password when it is requested by the remote Modem module.
11. Callback causes the Modem module to automatically disconnect and dial a predefined
telephone number after receiving an incoming call from a remote STEP 7--Micro/WIN.
Select the Enable callback checkbox and click the Configure Callback... button to configure
callback telephone numbers. Click Next>.
12. The Configure Callback... screen allows you enter the telephone numbers the Modem
module uses when it answers an incoming call. Check the 'Enable callbacks to only
specified phone numbers' if the callback numbers are to be predefined. If the Modem
module is to accept any callback number supplied by the incoming caller (to reverse the
connection charges), check the 'Enable callbacks to any phone number' selection.
If only specified callback telephone numbers are allowed, click the New Phone Number
button to add callback telephone numbers. The Callback Properties screen allows you to
enter the predefined callback telephone numbers and a description for the callback number.
The callback number entered here is the telephone number that the Modem module uses to
dial when performing the callback. This telephone number should include all digits required
to connect to an outside line, pause while waiting for an outside line, connect to long
distance, etc.
After entering a new callback telephone number, it must be added to the project. Highlight
the telephone number in the Available Callback Phone Numbers column and click the right
arrow box to add the telephone number to the current project.
13. You can set the number of dialing attempts that the Modem module makes when sending a
message or during a data transfer. The Modem module reports an error to the user program
only when all attempts to dial and send the message are unsuccessful.
Some telephone lines do not have a dial tone present when the telephone receiver is lifted.
Normally, the Modem module returns an error to the user program if a dial tone is not
present when the Modem module is commanded to send a message or perform a callback.
To allow dialing out on a line with no dial tone, check the box, Enable Dialing Without Dial
Tone Selection.
14. Version 1.1 of the EM 241 Module can be programmed to answer after a specific number of
rings. The module will answer on the first ring unless another value is specified. You can
select the answering ring number between 0 and 20. Values of 0 and 1 will answer on the
first ring. The value of zero provides compatibility with the previous version of the EM 241.
When using Modbus RTU protocol, Version 1.1 of the EM 241 Module allows the user to
configure the module to answer only a specific Modbus address. You can specify Modbus
addresses between 0 and 247. An address of zero provides compatibility with the previous
version of the EM 241 and causes the EM 241 to answer any address.
15. The Modem Expansion wizard creates a configuration block for the Modem module and
requires the user to enter the starting memory address where the Modem module
configuration data is stored. The Modem module configuration block is stored in V Memory
in the CPU. STEP 7--Micro/WIN writes the configuration block to the project Data Block. The
size of the configuration block varies based on the number of messages and telephone
numbers configured. You can select the V Memory address where you want the
configuration block stored, or click the Suggest Address button if you want the wizard to
suggest the address of an unused V Memory block of the correct size. Click Next>.
16. The final step in configuring the Modem module is to specify the Q memory address of the
command byte for the Modem module. You can determine the Q memory address by
counting the output bytes used by any modules with discrete outputs installed on the
Creating a Program for the Modem Module Chapter 10
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