Half Duplex Master Or Slave; High Speed Connection To Telesafe Rtu - Bell 5902 Hardware Manual

5.3.4

Half Duplex Master Or Slave

Use this configuration to connect two or more modems on a two or four wire network. The
transmission of any modem will be received by all other modems on the network, when using a two-
wire connection or radios. This is the basic configuration of a typical radio network.
Use the settings below to establish communication. The settings can be tuned for faster operation
once communication is established. See the comments below for suggestions. When optimizing,
adjust one setting at a time and observe the effect before proceeding.
SWITCH
CS0
CS1
CD0
CD1
CL0
CL1
AS0
AS1
SC0
SC1
CSH
FDX
RCD
TST
5.3.5

High Speed Connection to TeleSAFE RTU

Use this configuration to connect to a TeleSAFE 6000 or TeleSAFE 6000-16EX RTU with a model
6902 modem, or to a TeleSAFE VS/3 RTU. Both modems are half duplex Bell 202 modems, for use
on two or four wire networks or radios. They have a radio key control output. Soft carrier turn-off
and radio carrier detect are not implemented.
5902 Bell 202 Modem Hardware Manual
October 19, 2007
SETTING COMMENTS
closed Adjust these switches to transmit a shorter carrier
before data transmission commences. Ensure this
closed
delay is longer than the receiving modems' CD
delay, plus any propagation delays in the
communication system.
open Adjust these switches for a longer delay, to prevent
noise at the beginning of each reception. Ensure
open
that the transmitting modem's RTS/CTS delay is
longer than this CD delay, plus any propagation
delays.
open Adjust these switches for a shorter delay, once
communication works. If the received signal is
closed
weak or the CD led flickers off, restore this setting.
Carrier loss delay will not protect against data loss
but can prevent a jittery DCD signal.
adjust Add anti-streaming as required to protect the
network against excessive transmission length.
The maximum transmission length determines the
anti-streaming time.
closed Use the shortest SCT time that prevents carrier
turn-off noise. The SCT time can also be used to
closed
transmit a quiet period at the end of each message
if the receiving modem does not recognize soft
carrier turn-off.
close Open CSH switch to shorten carrier transmission
after data is sent. See also SCT switches above.
Carrier extension equals SCT delay plus CSH
delay.
open Half duplex must be selected.
adjust Open if RF carrier detect input is not used. Close if
RF carrier detect input is used.
open Close switch to engage half duplex tone
transmission test
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