IDEC WindSRV - Manual (Page 37)

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KEPServerEX5 Help
Configuring the Initiating Modem
This server uses the Windows TAPI interface to access modems attached to the PC. The TAPI interface was designed to
provide Windows programs a common interface that could be accessed by a range of modems existing in a PC. A set of
drivers for the Windows OS, which are provided by the modem's manufacturer, must be installed before the server can
use the modem in a project. The Windows Control Panel can be used to install new modems. For information regarding
modem installation and setup, refer to both the Windows and the modem's help documentation.
Once the modem has been properly installed, users can begin using it in a server project. The receiving end, or the
device modem, needs to be properly configured before it can be used. Each driver contains a Modem Configuration
page in its help file. This page contains a listing of the receiving modem's active profile. Users will need to confirm that
the receiving modem matches the profile provided by the driver.
Configuring the Receiving Modem
Use the Hyperterminal program that is included with Windows to configure the Receiving Modem easily. For more
information, follow the instructions below.
1. Use an available Serial Port to connect the desired receiving modem to the PC. Start Hyperterminal and then open
a new connection. Name the new connection ModemSetup.
2. In the invoked Connect To dialog, click in the Connect Using drop-down menu and select the communication port
to which the receiving modem is attached. Although other modems may appear in this list, they should be ignored for
the moment.
3. In the COMx Properties dialog, configure the communications port settings that will be used to talk to the receiving
modem.
Important: The COMx Properties settings must match the Baud Rate, Data Bits, Parity and Stop Bits used by the
target device. Modems remember the Baud Rate, Data Bits, Parity and Stop Bits that were used to talk to it last; thus,
if the receiving modem was configured at 19,200 baud but the device was configured for 9600 baud, the modem will
never be able to speak to the device. Although it could connect, the receiving modem would send all the data to the
device at 19,200 baud. This is true even if the modem connects at 9600 baud or if the transmitting modem is being
spoken to at 9600 baud. Any disparity between the settings will cause the modem application to fail. To avoid the error,
match the settings between the newly created server project and one that has a direct cable connection.
4. Next, enter the port settings. Then, click OK.
Note: At this point, users should be able to issue commands to the receiving modem. On many modems, this can be
tested by typing ATI4 followed by Enter. To ensure this is a valid test for a specific modem, refer to its help
documentation. If the modem is properly attached to the PC it will respond by displaying its current profile settings.
5. Set the receiving modem's desired profile and then save the settings by issuing a write command to the modem. To
do so, type AT&W0 followed by Enter. To test the receiving modem's configuration afterwards, simply turn it off for a
moment and then turn it back on. Next, type AT14 followed by Enter (or another applicable command). The modem
should display its current profile, including any changes that have been made.
Important: The profile settings and reference documents provided here are to be used as examples. Because of
different configuration commands and codes that may be used among modem manufacturers, refer to the specific help
documentation to verify all settings.
Cables
Before the project is ready to be used, users need to configure the correct cable connection between the receiving
modem and the device. There are 3 cables necessary for this: the existing device communication cable for direct
connection, a NULL modem adapter and a NULL modem cable. A NULL modem cable, in which all the pins are
connected to the same pins on both ends of the cable, is connected to the modem. The device communication cable,
used to connect to the target device, usually has pins 2 and 3 reversed. Since the cable being used to talk to the device
for the direct connection is obviously working properly by this point, users can use it on the receiving modem by
attaching a NULL modem adapter. Similarly, a PC modem cable will run from the PC to the initiating modem. With the
cables in place, users are now ready to use a modem in their application.
Note: NULL modem adapters can be found at most computer stores.
Example: Server Side Modem Configuration
After the modems have been properly configured and installed, users can enable their use with the server. At this point,
users should refer back to the direct connect project completed earlier when testing the device configuration and
communications.