Modems at the I/O Device

You can have multiple I/O Devices connected to a single modem if they have the same communication requirements (phone number, baud rate, data bits, stop bits, and parity). A separate port and modem needs to be used for each remote I/O Device with different communication requirements.

When deciding how many modems to use, consider the following:

• Once an I/O Device has been contacted, the connection can be retained for other I/O Devices in the group. If the I/O Server needs to request data from another I/O Device with the same communication details, it will wait until the current request has been completed, then it will use the same connection to make the second request.You can configure your modem to initiate telephone calls (call Plant SCADA), and/or receive telephone calls. This is done independently of Plant SCADA.

  Note: Wherever your modem is, you need to verify that its Data bits, Parity, Stop bits, and Serial Port Speed settings are compatible with the remote I/O Device as defined by the device's manufacturer or your communications link will not work.

See Also

Modems at the I/O Server