Broadcast Tools® SRC-8, 8 Channel Serial Remote Control
Broadcast Tools® SRC-8, Serial Remote Control
Page 6
Courier Modems in Leased Line Async Model
It is always best to bench test a leased line configuration. It is much easier to make configuration
changes when the modems are connected to each other in the same room rather than when they two
miles apart.
Below is a list of what needs to be done to set up both modems for leased line connections. This
document assumes you have two Courier V.34 modems with the current firmware revision.
The leased line should be an Analog 2 wire full duplex with no conditioning. The modems transmit
at -9dbm and will receive anywhere between -9dbm and -46dbm.
Line Specifications:
•
3002 type D circuit 2 wire connectors at each end of Leased Line.
•
Full duplex (both ends can transmit and receive at the same time).
•
Not mandatory but a Class A test to check the line from point to point (there may
be a charge for this by the phone company).
•
For dedicated line (the standard phone line included w/modem) the limit is 5
(five) miles. Otherwise, if the line is true leased line with power provided by the
Telco Central Office, then there is no limit on length.
•
No echo suppression.
•
No line conditioning.
•
Voice grade line.
NOTE:
Lease line must be a 2 wire line, not 4 wire and not a digital line.
1.
Connect the modem to the computer running communications software in terminal mode (i.e.,
HyperTerminal or Windows Terminal). Configure the communications software to match the data bit
construction of the device/computer that the modem will be connected to when it is on the leased line.
Data bit construction refers to the port speed or baud rate, parity, data bits and stop bits.
2.
Put DIP switches 3,5, 8 and 10 down to set them in the on position for both modems. This will load the
factory defaults.
3.
If the computer system the modem will be connected to will be using
Hardware Flow Control
then type
the following in your communications software or terminal: (Use this one)
AT&F&B0&H0&I0&K0&N6&R1&S0&L1&W <enter>
4.
Modem 1 is the Answer Modem. Change the DIPswitches on Modem 1 so that 1 and 4 are down to
set them in the on position and all other are up or off.
5.
Modem 2 is the Originate Modem. Change the DIP switches on Modem 2 so that 1, 4, and 5 are down
to set them in the on position and all others are up. Put the Originate modem at the studios.
6.
Power off both modems. Connect one of the phone cables that comes shipped with the modems from
the RJ11 jack labeled “JACK” on Modem 1 into RJ11 jack labeled “JACK” on the Modem 2. These are
the Telco jacks on the modems, which are closest to the RS-232 cable connector.
7.
Power on both modems. The modems will begin handshaking and connect. Ensure that this
configuration works with the software you plan to use with your leased line configuration. Finally, take
the modems to the actual leased line for installation.
8.
Standard (modem) male 25 pin D-Sub to modular adapter wiring information: Configure the adapter as
follows:
Pin 2 = Yellow
Pin 3 = Green
Pin 7 = Red
