Datalogic DLR-TL001, Product Reference Manual

Histogram Description

10

DLR-TL001

Remaining Shelf Life calculation

Shelf Life is the length of time that perishable items are given before they 

are considered unsuitable for sale or consumption. For many products the 

spoilage rate increase of a perishable good is an exponential function of 

temperature.
As well as the MKT, the remaining Shelf Life calculation is useful in order to 

monitor the status of an item during the shipment. The DLR-TL001 calcu-

lates the remaining Shelf Life by using a linear approximation of the Arrhe-

nius algorithm at each new sampling time. Shelf Life time can be en-/dis-

abled toggling the state of the ARRE flag in the 

Control Register (RW) on 

page 14

. 

The remaining Shelf Life (in hours) is calculated with the following formula:

where SHLref is the Shelf Life reference expressed in hours, Tn is the tem-

perature of the different samples expressed in °C, Tref is the reference tem-

perature expressed in °C, Q10 (unit less number) is defined as the ratio of 

the reaction rate constants at temperatures differing by 10 °C from the ref-

erence temperature and tn is the sampling interval expressed in minute for 

the selected bin.
The user can set a threshold value for the remaining Shelf Life; if the 

remaining Shelf Life is lower than the threshold, the tag generates an alarm 

setting to 1 the SHL_ALARM bit in the STATUS register. The remaining Shelf 

Life value can be obtained reading the SHL_TIME register while the threshold 

can be set writing the desired value in the SHL_THRESHOLD register.
The remaining Shelf Life value can be obtained reading the SHL_TIME regis-

ter while the threshold can be set writing the desired value in the SHL_-

THRESHOLD register.

Battery measurement and behavior

The DLR-TL001 tag includes a battery measurement circuitry that allows to 

control the battery charge level. 
Four battery charge levels are defined: Full (3), Normal (2), Low (1), Empty 

(0); values can be obtained reading the BAT_LSBIT and the BAT_MSBIT in the 

STATUS register. The DLR-TL001 tag  behave normally when the battery is at 

the Full or Normal battery level, while it is automatically put in Sleep state 

when the level reach the Low value.
When the battery level status is Low (1) or Empty (0) the battery level is con-

sidered critical so the condition is reported by the manual interface as 

described in the relevant paragraph.