4.10 Serial Terminal Management

The serial terminal interface has some security and configuration commands that the user must access if a serial terminal is to be used. The following describes the configuration and control commands relating to the serial terminal interface.

Set Baud Rate Access: CONFIGURATION
(cnfg) (538) ; (rate#)
Response: "S B R" plus baud rate

The FF-800 supports eight baud rates from 75 to 9600 baud. the following list correlates (rate#) with the appropriate baud rate:

(rate#)Baud rate
The new baud rate takes effect after the FF-800 is reset. Thus, this command must be followed by a warm or cold reset before the new baud rate becomes valid.

Modem On Line Access: CONFIGURATION
(cnfg) (536)
Response: none

This command issues the "ATA" modem command via the serial port. This Hayes command causes a modem connected to the FF-800 serial port to go off hook in the answer mode. The user may program this modem control string via the DCECON command (Serial Terminal, see chapter 5). This command allows the user to call up on the control autopatch and still have "on-demand" access to the modem if desired. In order to take full advantage of this connect method, the user must route the telephone line first through the modem and then to the FF-800 phone line jack (see figure 4.10.1). The user's modem would be connected in a similar manner except that the device that follows the modem is the telephone from which the control autopatch would originate. This connection protocol allows each modem to go off hook and automatically disconnect the user's telephone and the FF-800 autopatch, respectively.

In addition to the phone line connection, the user must issue a couple of Hayes commands to allow their modem to go off hook in the originate mode without any call progress detection. The "ATX0" command disables the call progress detection (dial tone detect, ring detect, etc...) and must be entered before attempting to connect to the FF-800 modem. Once the call progress detection is disabled, the user issues the Modem On Line command via their telephone. When the FF-800 modem carrier is heard, the user types "ATD {enter}" at their terminal to initiate the connect sequence. At this point, the modem should respond "CONNECT". The FF-800 is ready to accept serial commands (see chapter 5 for details on using the serial terminal interface).

The user should note that the FF-800 is still in the control autopatch mode and this must be disabled before the modem connection is terminated. HANG (chapter 5) allows the user to de-activate the control autopatch from their serial terminal. However, the user may leave their phone off hook if they desire to return to the control autopatch after they have finished with the serial terminal (this only works if the modem automatically de-activates the connection to the "phone out" connector). After the user enters the "+++ ATH" sequence, the two modems will go on hook and the FF-800 will be reconnected to the phone line (as will the user's phone) -- control autopatch commands may then be entered at will.

Modem Up/Down Access: CONFIGURATION
(cnfg) (535) ; (on/off)
Response: "O K"

There are two message assignments in the message data base that can be used to control the auto-answer status of a modem connected to the serial port of the FF-800. The default messages issue the Hayes standard commands "ATS0=0" for modem (off) and "ATS0=1" for modem = (on). If the user has a non-standard modem, or is using a TNC as a modem, the appropriate control strings can be entered and assigned by the user as desired. The DCEDN and DCEUP commands (Serial Terminal, see chapter 5) are used to view and/or program the modem (off) and (on) strings (respectively).

DD538			interrogate baud rate
"S B R Ninety Six Hundred"
DD5383			set 2400 baud
"Set S B R Twenty Four Hundred"
AA4			execute warm reset
"F F Eight Hundred V x.xx ...."
DD5351			set modem for auto answer
"O K"
(cnfg) (539) ; (on/off)
Response: "D T M F Echo" plus "On" or "Off"

If the DTMF log echo mode is activated, the FF-800 will echo all DTMF characters received to the serial port. The format is the same as the listing provided by LLOG (section 5.5) and includes a date/time stamp with each entry. In order to eliminate interference from the serial terminal feature, the log will only echo if the serial terminal interface is logged off. During logon, the echo is prohibited. This feature allows the DTMF log to be continuously saved to disk, or to an on-site printer for later reference.

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