Teledesign Systems Inc TS4000EH Manuel D’Utilisation

Clear Channel 
Scan 

Activates Clear Channel Scan Operation (see below). 

The bottom box is the scan list which indicates the channels 
that will be scanned.  The scan list can be changed with 
the channel box, add button and delete button. 

 
Channel List 

The bottom box is the scan list which indicates the channels 
that will be scanned.   

Channel Box, 
Add Button, 
Delete Button 

These controls are used to change the channel numbers in 
the channel list. 

CCS Remote 
Operation 

When this is checked the TS4000 will transmit on the same 
channel that it last received a packet from another TS4000. 

This function is useful for systems where a unit (the CCS 
Remote) needs to respond back to another TS4000 that is at 
an advantaged site (a site that has wide radio coverage and 
therefore can hear interference that the CCS Remote does 
not hear).  By transmitting back on the same channel as the 
advantaged unit, the CCS Remote unit minimizes the 
likelihood that it chooses a channel with interference. 

 
When Clear Channel Scan operation is enabled, the TS4000 will automatically 
and dynamically select the least congested channel from the clear channel scan 
list.  This operation is completely transparent to the host equipment and does not 
require any operator intervention. 
 
When clear channel scan is enabled, all of the TS4000s (both transmitters and 
receivers) constantly scan the channels of the scan list looking for valid TS4000 
transmissions and also looking for interference (noise or transmissions from 
other sources).  The TS4000s keeps track of the amount of interference on each 
channel.  Before transmitting, a TS4000 will select the best channel and switch to 
the channel with the least amount of interference.  The receiving TS4000s will 
then see this valid TS4000 transmission during their scans and receive the 
packet. 
 
To insure that receiving TS4000s have time to detect and lock up to the 
transmissions, the transmit preamble time is increased based on the number of 
channels on the scan list.  Note that the transmit attack time can be read out of 
the modem with the Retrieve Radio Hardware command. 
 
For systems that require very high reliability at some or all sites, Teledesign has 
a Redundancy Switch that provides hot standby redundancy for the TS4000.  
The Redundancy Switch requires two TS4000s and can be used with one or two 
power supplies and one or two external amplifiers. 
 
When using the TS4000s with the Redundancy Switch, the TS4000s can be 
configured with any of the options.  However, it is essential that the two 
redundant modems are configured identically except of the Enable 
Redundancy settings.