To change settings for the RTU's Modem (not the modem for the computer running Alarmware™), either connect to, or work offline with, the desired RTU. Select Devices from the Configuration menu.
In the tabbed "Device Settings" dialog box select the "RTU Modem" tab:
WARNING - An incorrect value entered for the RTU Modem Initialization String may disrupt access to the RTU. Please make certain you are entering a valid RTU Modem Initialization String.
The RTU Modem Initialization String field is used to tailor the performance of the RTU modem for special data communication situations. AT command set values may be entered into the initialization string. However, it is advised that you do not enter AT commands unless you thoroughly understand the impact of AT commands, or you have consulted with the RACO Customer Service Department.
The RTU re-initializes its internal modem at various times, such as whenever it needs to make outgoing calls or when it begins making voice reports. It is during re-initialization that the RTU Modem Initialization String is sent to the RTU modem. See Possible Useful AT Commands.