Western Telematic CMS-16 manual Modem Mode, Port Buffers

7.3.2. Port Buffers

The Status Screen lists the amount of Buffer Memory currently used by each port. The CMS uses buffer memory in two different ways, depending on the user-selected port mode.

●Any-to-Any, Passive, and Modem Mode Ports: When two ports are communicating at dissimilar baud rates, the buffer memory prevents data overflow at the slower port.

●Buffer Mode Ports: Stores data received from connected devices. The user issues a connect command (/C) from an Any-to-Any Mode or Modem Mode port to retrieve data.

If the Status Screen indicates an accumulation of data, the /E (Erase Buffer) command can be invoked to clear the buffer.

7.4. Modem Mode

In addition to allowing data transfer, the Modem Mode also provides additional functions specifically related to modem communication. A Modem Mode Port can perform all functions normally available in Any-to-Any Mode. The Modem Mode is available to all CMS ports except the Network Port.

When the Modem Mode is selected, the port configuration menu (command /P) will display three additional prompts, which allow the user to re-define the modem reset string, initialization string, and hang-up string.

When the Modem Mode is selected for a port with Supervisor Level command access, the Supervisor Password should be defined. This will discourage unauthorized access to higher command functions.

When a call is received, the unit will prompt the caller to enter a password. The CMS allows three attempts to enter a valid password. If the correct password is not entered in three attempts, or if the user does not respond to the password prompt within 30 seconds, the modem will disconnect.

The password can be defined and enabled by invoking the /P command as described in Section 5.5.

Note:

●When a Modem Mode Port exits Command Mode, or the DCD line is lost while the Command Mode is active, the CMS will pulse the DTR line to the modem. The unit will then send the user-defined modem command strings to make certain the modem is properly disconnected and reinitialized.

●When an external modem is installed at a CMS port, other ports can use the modem for calling out. To call out, invoke the /C command to connect to the port, and then access the modem as you normally would.