Configuring a VT-MODEM Using the VT-MODEM Setup Wizard:
It is highly recommended that the Sixnet VT-MODEM Setup Wizard be used for VT-MODEM
configuration. Simply check the appropriate boxes, choose the appropriate communication settings from the
dropdown lists, and load the configuration into the VT-MODEM. This utility does not require user
knowledge of AT commands and S-registers.
Refer to the online help system in the VT-MODEM Setup Wizard for instructions and application notes.
Note: The VT-MODEM Setup Wizard must be used to configure the self dial parameters of the VT-
MODEM-2 and the RS422 / RS485 port parameters of the VT-MODEM-3.
Setting the Modem's Baud Rate for the PLC
The VT-MODEM has an automatic baud rate detection feature that lets the modem recognize commands through its
serial port at any supported baud rate. However, if the modem is connected to a device that does not send commands or
data unless spoken to (such as most PLCs), then the modem will pass information from the phone line to its serial port
at the last auto-detected baud rate. This is typically the baud rate used by the VT-MODEM setup Wizard when
configuring the modem.
The VT-MODEM is defaulted at the factory for 9600-baud. To change this setting, connect the modem to a PC. Start
the VT-MODEM setup Wizard and choose the baud rate that matches the PLC’s baud rate. Then choose the
appropriate settings and write the configuration to the modem. Exit the VT-MODEM setup Wizard and reconnect the
modem to the PLC. (Be sure to cycle power to the modem.) Call the modem and verify that the PLC is responding to
commands.
VT-MODEM User Manual
Page 16 of 30
Last Revised: 17-Aug-09
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