Instructions
UM-0085-B09  DT80 Range User Manual  Page 301 
RG 
Note: any Ethernet and USB connections are terminated whenever the DT80 goes to sleep – which is why the DT80 will by default 
disallow sleep while either of these ports are connected. 
Some of the above conditions can be overridden using the P15 parameter, as follows.  
Setting 
Result 
P15=0 (default) 
Allow sleep, but not if externally powered or if Ethernet/USB is connected 
P15=1 
Allow sleep, but not if Ethernet/USB is connected 
P15=2 
Do not allow sleep 
P15=3 
Allow sleep 
P15=4 
Allow sleep, but not if externally powered 
For example, if you set P15=3 then the DT80 will be allowed to go to sleep, even if the logger is externally powered or 
Ethernet/USB is connected. 
Forced Sleep Mode 
The DT80 provides some protection against gradual power failure (e.g. the internal battery becoming discharged). If it 
detects that the supply voltage is becoming critically low (terminal voltage less than about 5.5V), the DT80 will 
automatically close all store files and force the unit into sleep mode. The DT80 will remain asleep until the power supply 
recovers to an adequate level. During this time schedules will not
 execute. 
Once power is restored, a hard reset will occur. 
An entry will be added to the Event Logs (P276) any time that the DT80 enters forced sleep mode. 










