Filter
Top Products
Basic Requirements
for Modems
●
●
●
●
●
●
●
●
●
Requirements for
Outgoing Modem
Pools
The following paragraphs describe the basic requirements
for any modem, and specific requirements when used in
outgoing and incoming modem pools.
NOTE:
Modems
can meet these requirements through
fixed features or through hardware and software
options that can be set. An option setting may
make a modem appropriate for one pool in the
MERLIN II system but not another.
The basic-requirements for modems are the following:
Full-duplex operation, for switched networks
A single speed between 300 bps and 19,200 bps
Serial transmission of characters in a binary
asynchronous format
EIA RS-232-C interface
Peak signal level compatible with the MERLIN II
system
Modular jack connection for telephone network
Loss of earner disconnect so that the modem goes on-
hook and turns received line signal detector, EIA lead
RLS (carrier on) off
Disconnect if EIA lead DTR (data terminal ready) goes
off
Passing of break character and long space signal
Saving of options during power outage
In addition to meeting the basic requirements, a modem
used for outgoing calls must have the following
characteristics:
System Connectivity 1-59