RF Channel – This sets the radio channel used by the transmitter.
Transmission Interval – This is the time between new messages and it is specified in seconds. It can be set from a minimum of 1 (1sec) to 2592000 (30 days).
Retries – This is how many times the unit re-transmits the message. Sending the message more than once increases the likelihood the message will be received. Total messages sent = Original message + no. of retries. For ex: If the unit were programmed to send five transmissions; Retries would be set to four.
Retry Min Sec and Retry Max Sec – If the message is sent more than once; i.e., Retries is not set to 0. These two parameters determine the time between retransmissions. Retry Min Sec is the minimum time between repetitions of the message. Retry Max Sec is the maximum time between repetitions of the message. The unit will randomly select a time between Retry Min Sec and Retry Max Sec to retransmit.
Retry Min Sec is specified in seconds. Retry Min Sec can be set from a minimum value of 5 seconds to a maximum of 300 seconds.
Retry Max Sec is specified in seconds. Retry Max Sec can be set from a minimum value of 10 seconds to a maximum of 600 seconds.
Globalstar recommends that the retransmission interval be approximately five minutes (300 seconds). To set a retransmission interval of five minutes, set Retry Min Sec equal to 290 seconds, and set Retry Max Sec to 310 seconds. This will provide plus or minus 10 seconds jitter around the 5 minute retransmission interval.
All retransmissions must be completed before the next new message is transmitted. The system will give an error if this constraint is violated. For example, the following parameters are not valid: transmission interval set to 1 hour, Retries set to 9, Retry Min Sec set to 9 minutes and Retry Max Sec set to 10 minutes. Nine retries at 9 to 10-minute intervals requires 81 to 90 minutes; whereas the next new message is set for 60 minutes.
Important Note: There should not be more than 16 transmissions within the time frame as represented by the following formula. Message time frame = 2* (RetryMaxSec * Retries) + (No. of Packets * 2.36).
If more than 16 distinct messages are transmitted within the above time frame then those messages are considered as duplicate.
Offset – This parameter controls the predictability of the new messages. If random is selected, the new messages will be transmitted randomly around the transmission interval.
Power Level – This sets the transmitted power level. This parameter is set when the unit is installed. For most installations, the low power level is appropriate. However, if there is blockage by trees, the high power level should be chosen. Note that high power level depletes the battery faster.