Black Box LRS002A-R2, LRA005A-R2 manual Modem Control Signals, 258, Dialup iface loginpwd loginpwd

ASYNC ROUTER AR-P, AR-5, AND SYNC ROUTER REFERENCE MANUAL

The $LOGIN_PWD macro sends the login_pwd value previously specified by the command:

dialup iface login_pwd login_pwd

To change a phone number, login name, or login password, simply reissue the appropriate dialer command. The dialer command file remains the same.

B.5 Modem Control Signals

The Router contains an internal modem for each external connection through a telephone line. Data and control signals connect the internal modem and the Router CPU. These signals between the modem and computer parts of the Router may be useful to monitor when troubleshooting problem connections. To facilitate monitoring, some of these signal circuits have LED external indicators. The status of others may be monitored through the software command asystat.

The LEDs labeled Tx, Rx, DTR, and DCD on the modem card at the rear of the Router indicate the following:

Tx—Transmit Data

Flickers when the Router is sending modem commands or data to the modem.

Rx—Receive Data

Flickers when the Router is receiving data from the modem. Also flickers together with Tx when the Router is sending commands to the modem. With some experience, you can get an idea of line use by watching these lights for an active connection.

DTR—Data Terminal Ready

Normally lit if a dialer is active on the modem port. When the dialer is terminated with a dialup modem inactive command, DTR goes off. When DTR is off the modem will not answer incoming calls. When a connection goes idle, the Router hangs up the telephone connection by turning DTR off for a moment until DCD goes off.

DCD—Data Carrier Detect

Sometimes called Received Line Signal Detect, or RLSD. Also referred to as CD. Indicates that the modem has established a data path to a remote modem. The LED is lit when connected and off when listening or dialing.

The status of the other modem control signal can be displayed with the asystat command. The signals are:

RTS—originally Request to Send

In the Router, indicates that the Router is able to receive data from the modem. Usually on, except briefly during heavy incoming traffic.

CTS—Clear to Send

Indicates that the modem is able to receive data from the Router.

RI—Ring Indicator

Indicates an incoming call is ringing this phone line. This signal comes on briefly. If DTR is on, the modem will immediately answer.

DSR—Data Set Ready

Generally always on. If asystat does not show DSR ON, the modem is probably defective.

CD—Carrier Detect

See the definition for DCD above.

Control the Modem Speaker’s Volume

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