Slave terminal, monitoring system, and wireless transmission method

A slave terminal comprising:

• a data transmission unit that wirelessly transmits status data relating to a condition of a monitoring target to a monitoring apparatus in response to a transmission trigger at every fixed period;
• a reply check unit that determines whether or not an ACK signal was sent back from the monitoring apparatus in response to the status data that was transmitted;
• an adjustment value calculation unit that determines an adjustment period of a random length when the reply check unit has determined that there was no reply;
• a timing update unit that outputs a measurement start trigger after the adjustment period has elapsed when the reply check unit has determined that there was no reply, the timing update unit outputting the measurement start trigger without the adjustment period when the reply check unit has determined that there was a reply;
• and
• a trigger generation unit that outputs the transmission trigger after counting the fixed period in response to the measurement start trigger.

A slave terminal comprising:

• a data transmission unit that wirelessly transmits status data relating to a condition of a monitoring target to a monitoring apparatus in response to a transmission trigger at every fixed period;
• a reply check unit that determines whether or not an ACK signal was sent back from the monitoring apparatus in response to the status data that was transmitted;
• an adjustment value calculation unit that determines an adjustment period of a random length when the reply check unit has determined that there was no reply;
• a trigger generation unit that sequentially generates the transmission trigger at the every fixed period;
• and
• a timing update unit provided to the trigger generation unit, the timing update unit shifting timings of generation of the transmission triggers that are sequentially generated thereafter from a current timing of generation of the transmission trigger by the adjustment period when the reply check unit has determined that there was no reply.