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CHAPTER 3. LEASED LINE OPERATION
ACTIVE Professional External Modem User’s Manual
9
CHAPTER 3. LEASED LINE OPERATION
This chapter tells you how to establish a leased line connection in asynchronous and
synchronous modes.
What is Leased Line Operation?
In leased line operation, two modems are directly wired together by a dedicated
telephone line. The register S7 does not pose a time limit on making a data connection.
One modem must be set to originate mode and the other must be set to answer mode.
ACTIVE modem is designed to be used with a 2-wire / 4-wire(optional) leased line
The RS-232C DTR signal must be ON to maintain the leased line data connection. If
the modem detects a DTR drop during data connection, the carrier will be dropped.
Once the DTR signal is restored to ON, the modem will re-start to establish data
connection. The user can use the AT&D0 command to cancel the effect of DTR status
on this operation. In this case, the modem will perform this operation disregard of the
DTR status.
Asynchronous Power-on Leased Line (POLL) Operation
When the modem is set to POLL mode, the carrier is transmitted immediately upon
powered up. The modem will wait for the remote carrier eternally until data
connection is established. If the modem detects a loss of carrier during data
connection, it will send the carrier for a re-connection automatically.
The following is an example to establish a Power-on 2-wire leased line (POLL)
operation, Please follow the instructions below:
1. Make proper wiring connection.
2. Prepare two modems. One modem set to Answer mode, another one set to
Originate mode.
Method:
Set
Normal / Config.
Switch to POP position for Normal mode. Toggle the
O/A
switch to Answer mode or Originate mode. The LED segment displays
‘A.’ for Answer mode, or ‘O.’ for Originate mode.
3. Set desired DTE speed, protocol, transmission mode, flow control, etc.
Method:
Set
Normal / Config.
Switch to PUSH position for Config mode.
DTE speed: For example, if 57600 bps DTE speed is required, toggle the
Menu
Switch to Menu 4 (DTE speed menu), the digit ‘4’ is shown on the
LED segment. Then toggle the
Function
Switch to Function 2 (speed 57600
bps is selected), the digit ‘2’ is shown on the LED segment.