Teledesign Systems Inc TS4000EH Manuel D’Utilisation

Control Description 
Provide Address 
at Receiver 

When this control is activated, the source address of each 
received packet is sent as a prefix status string to the data 
(see Control and Status Strings). 

Provide Positive 
Transmit ACKs 

When this control is activated, a status string is sent to the 
user when an acknowledgment is received for a packet.  
The corresponding packet number of the packet will be 
provided as part of the status string (see Control and Status 
Strings). This does not apply to any type of broadcast 
transfer or individual transfers without acknowledgment. 

Provide Negative 
Transmit ACKs 

When this control is activated, a status string is sent to the 
user when the transfer of a packet is unsuccessful (all 
retries have been sent and no acknowledgment has been 
received).  The corresponding packet number of the packet 
will be provided as part of the status string (see Control and 
Status Strings). This does not apply to any type of 
broadcast transfer or individual transfers without 
acknowledgment. 

Provide RSSI at 
Receiver 

When this control is activated, the RSSI (Receive Signal 
Strength Indication) of the received packet is sent as a 
prefix string to the data. 

The string is made up of ASCII characters as follows: 

+TSRxxx 

where xxx = receive signal level in –dBms  

    (i.e. +TSR087 = a –87dBm signal level) 

Note that because the value is in –dBms (negative dBms) a 
larger receive signal is represented with a smaller 3 digit 
number. 

For serial port 1 this control is on the Serial Port 1 Tab. 

 
Control Description 
Min Idle Slots 

This sets the minimum number of idle slots before a 
modem attempts transmission (see Setting Min Idle Slots). 

If the minimum number of idle slots is set to zero the 
modem randomizes its transmission attempts with the first 
slot after the channel becomes idle.  For values greater 
than zero, the modem waits that many slots before 
randomizing its transmission attempts. 

Tx Index 

The transmission index (TI) is the inverse of the probability 
of transmitting in an idle slot.  An index of 4 corresponds to 
a 1/4 or 25% chance of transmitting in an idle slot.  The 
goal of setting TI is to maximize efficiency on the channel.  
If TI is set too low then transmissions collide too often.  If TI 
is set too high then there is excessive unused channel time 
in the system (see Setting Transmission Index). 

 
Min Idle Slots and Tx Index can be set differently for different types of packets.  
The following table describes the different packet types.