Specifications

October 8, 2003 Networking Alpha Signs (9700-0112C)
16 Modem networks
Modem networks
Modem—Preliminary information
In a modem network, messages are sent from the PC to a modem, called the transmitting modem, over
telephone wires to another modem, called the receiving modem, and then to a sign. A US Robotics 56K modem is
used for the receiving modem and must be configured before it can be used to send data to a sign. The transmitting
modem is the responsibility of the sign owner (the same brand is recommended).
If you are using a US Robotics 56K modem for the receiving or transmitting modem, or both, the dip switches
on them should be set as follows:
You will need to send commands to the receiving modem from either the modem’s software (here, it is US
Robotics Control Center software) or Microsoft’s HyperTerminal software.
Refer to TechMemo 01-0011, Modem Setup for Alpha signs, for additional information on configuring your
modem. (This TechMemo is available at http://www.adaptivedisplays.com.) Also, since the commands necessary
to change the modem’s settings vary between modems, the modem’s operations manual should always be
consulted.
On some signs, an internal jumper must be set to either RS232 or RS485 depending on the cabling the sign is
using. See “Appendix D—Setting the RS232/RS485 jumper” on page 53. Also, some signs may need to be
terminated depending upon which type of network and the number of signs you are using. See “Appendix B—
End-of-line termination” on page 50 for additional information.
Disables
flow
control
Modem
ignores
RTS
Fixed serial
port rate
Connection
speed =
9600 baud
Loads
Profile Ø
into
NVRAM
when
modem is
powered
on.
Writes this
current
setup to
Profile Ø in
nonvolatile
memory
(NVRAM)
ON
12345678
3, 5, 8 = ON
1, 2, 4, 6, 7 = OFF
ON
12345678
2, 4, 5, 6, 7 = ON
1, 3, 8 = OFF
Transmitting modem
Receiving modem
AT&HØ&R1&B1&N6&YØ&WØ