Modems serve a variety of features in control systems, including communicating with I/O devices, providing a connection method for remote VTS application clients, and disseminating messages from the VTS Alarm Dialer. Because each of these modem uses is handled in a unique fashion, modem management must receive close attention such that VTS can determine what modem is capable of handling each type of communication and directs modem traffic appropriately.
This process is called modem pooling and allows VTS to manage a group (pool) of modems efficiently. When a modem is required for an outgoing voice call from the VTS Alarm Dialer, the VTS Modem Manager automatically searches its pool of modems for the next available modem capable of handling a voice call. The same process is followed for outgoing data calls. Similarly, any pooled modem can be configured to allow or deny incoming voice or data calls.
