referring to fig1 , a conventional postal box of the type commonly used by canada post indicated generally at 10 is shown retrofitted with a monitoring system according to the invention . the box 10 includes a monitoring unit 1 which is housed in a cap which can be fitted to the top of the postal box 10 to retrofit it . the hollow cap 1 includes a top 200 and sides 202 , 204 , 206 and 208 . the unit 1 is connected to surface mounted magnetic contacts 4 , 5 , 6 on doors 4 a , 5 a and 6 a respectively of the box 10 via wire 1 a . contacts 4 , 5 , 6 correspond to zones 1 , 2 , 3 of the monitoring system . wiring is used to connect the unit 1 to the contacts 4 , 5 and 6 via a surface mounted contact 3 , model gri29awh . a hollow tube 2 houses the wiring 1 a to keep it from interfering with the operation of the box 10 . the unit 1 is also connected by wire to a smoke detector 7 , model dscmn - 140 c . the smoke detector 7 corresponds to zone 4 of the monitoring system . other contacts or sensors can be used with the monitoring system depending upon operational requirements . for example , sniffer sensors for detecting bombs and biological agents placed inside the postal box 10 by terrorists can be used . temperature sensors can also be used to monitor temperature within and without the postal box . a gps system can also be incorporated into the system for tracking the position of the postal box should it be removed from its location by vandals or thieves . a potentiometer or mercury switch can also be used inside the postal box 10 and connected to the monitoring unit 1 to monitor whether the postal box 10 has been tipped or moved . all such monitoring devices are connected to the monitoring unit 1 in a similar fashion to the magnetic contacts 4 , 5 , 6 or the smoke detector 7 as described above . fig2 is a block diagram of a monitoring system according to the invention . the system is controlled by a microprocessor 20 integrated with a smart circuitry board low power controller ( discussed in more detail below ) which forms part of the monitoring unit 1 . inputs 21 to 24 are connected to the microprocessor 20 and are the inputs from the magnetic contacts 4 , 5 , 6 and detector 7 , respectively . the microprocessor 20 is also connected to a connector 26 which can be used to connect an external programming key pad ( not shown ) to the microprocessor 20 . microprocessor 20 is connected to three relays , 28 , 29 and 30 which in turn are connected to controlled devices 32 , 33 and 34 . the controlled devices 32 to 34 can be motor driven locks , for example , which can be activated to lock the doors of the postal box 10 in the event of a hazardous package being detected in the postal box 10 . the microprocessor 20 is also connected to a solid state power switch 36 which in turn is connected to a fast track system (“ fts ) radio 38 manufactured by numerex corp . of atlanta , ga ., u . s . a . ( other suitable wireless communications devices can also be used ). a serial data in / out connection 40 connects the microprocessor 20 to the fts radio 38 . the fts radio 38 communicates to a central monitoring station 42 via cellular network 44 . a solar panel 46 is connected to a battery voltage regulator 47 which in turn is connected to a rechargeable battery 48 and a microprocessor voltage regulator 49 and then to the microprocessor 20 to provide power to the monitoring system . the solar panel 46 charges the battery 48 . the regulator 47 down regulates the voltage from the solar panel 46 to 12v and the regulator 49 in turn down regulates the voltage to 3 . 3v , the operating voltage of the microprocessor 20 . referring to fig3 , and 5 , the low power controller of the invention includes a circuit board with a pic 16f870 - i / sp (“ pic ”) microprocessor for controlling the operation of the monitoring system of the invention . the pic microprocessor is designed to operate in a stand - by low power ( sleep ) mode and in a full power an active mode . the pic processor controls the operation of the controller using a control program comprised of code programmed in c ++. the pic microprocessor is connected to a 74hc4051 multiplexer . the multiplexer is connected to an rn2 resistor network . the rn2 resistor network is connected to a terminal strip connector cn 1 with input screws z 1 to z 6 and common screws c . the pic microprocessor is also connected to an spx 485 driver which in turn is connected to an rj45 jack which can be used to connect the controller to a hand - held key pad . the pic microprocessor is also connected to a max202ecp 9 (“ max ”) rs - 232 driver manufactured by maxim which in turn is connected to a db9 male plug . the db9 male plug is connected to an fts radio . the max rs - 232 driver converts the binary communication of the pic microprocessor to the rs - 232 protocol of the fts radio when the pic microprocessor is sending serial data to the fts radio . when serial data is received from the fts radio , the max microprocessor converts the rs - 232 communication of the fts radio to the binary communication of the pic microprocessor . the pic processor is also connected to relays which operate devices connected to the relays such as door locks . the solar panel unit is a high output micro - thin solar panel unit connected to a low drop - out voltage regulator manufactured by national semiconductor which is used to charge a 12 v 7ahr storage battery . a solar voltage (“ vsolar ”) monitor , a voltage output (“ vo ”) monitor , a battery voltage (“ vbatt ”) monitor are used to determine optimum conditions for battery charging . a 3v switch - mode regulator is used to power the low - power pic processor . power generated by the solar panel unit is used to charge the storage battery . the low drop - out regulator regulates the amount of charge given to the storage battery up to a defined maximum voltage such that the storage battery is not overcharged . the low voltage regulator maintains a constant voltage output when sufficient sun - light is falling on the solar panel . in operation , the pic microprocessor has a stand - by low power mode and a full power active mode . the pic microprocessor in the stand - by mode operates on a low power consumption of 5 to 6 milliamps of current which is normally supplied by the solar panel unit . if the solar panel unit is not operational , such as because it is covered with snow , power to the pic microprocessor is supplied by the storage battery . the 12v 7ahr rechargeable lead - acid battery used in the system has a stand - by life of about 10 to 11 days before it requires a recharge from the solar panel unit . the pic microprocessor operates on a normally closed input in stand - by mode as it waits for an open loop signal ( alternatively , a normally open loop input can be used ). when a zone is triggered , ( for example if a door is opened on zone 1 ), the input loop for that zone opens and the voltage on that zone goes to about 5v and the pic microprocessor goes into an active mode and turns on an electronic switch ( a field effects transistor manufactured by international rectifier ) which in turn switches on the fts radio . the triggered zone is an analogue input which is used by the pic microprocessor to generate an electronic alarm message corresponding to that zone input . the alarm message is stored in the scratch pad memory of the pic microprocessor . the fts radio then auto - enrolls itself into a cellular network which takes about 30 seconds . after the enrollment is complete , the fts radio sends a request to the pic microprocessor that it is now safe to send the zone input alarm message which has been stored in the pic microprocessor . the pic microprocessor waits for the enrollment before sending the alarm signal to the fts radio for transmission to a central monitoring station or other monitoring device . the message is received by the fts radio and the fts radio sends the message through the control channel portion of the cellular network . the pic microprocessor then switches off the fts radio to conserve power and starts a timer for a pre - set period of time so that subsequent triggered events will not be transmitted until the set time expires . after the time expires , the new event will restart the cycle described above . the relays and the fts radio require 12v dc for operation , the driver integrated circuits require 5vdc for operation and the pic microprocessor requires 3 vdc for operation . the fts radio operates at 100 milli - amps when it is energized . referring to fig5 and 7 , in another embodiment of the invention , the monitoring unit can be integrated into a postal box during manufacture . the postal box of fig5 , and 7 is constructed from fiberglass and includes a weighted base 110 to ground the box . the main compartment of the box includes two doors . the upper door 100 is for receiving mail and parcels . the lower door 103 is a pick - up door by which a mail / courier employee gains access to the contents of the box during a pick - up . the box includes a solar panel 105 which is affixed to the front of the box for locations where the box is located up against a building or a wall . the solar panel 105 is inclined slightly upwards toward the sky to capture the sun &# 39 ; s rays . alternatively , a solar panel 106 can be affixed to the inclined top of the box for open area locations . the monitoring unit is housed in a sealed compartment 108 or 107 next to the solar panel 105 or 106 as the case may be and connected to it . a hollow tube 104 attached to the inside of the box houses cables connecting the various contacts and sensors of the box to the monitoring unit 108 or 107 in a similar manner to the postal box shown in fig1 . for very remote or low sunlight locations , an additional battery ( not shown ) can be included in the base 110 and connected to the monitoring unit 108 or 107 using wiring which is carried inside a second hollow tube 109 . the box is equipped with remote lock - down devices which lock the doors 100 and 103 to prevent entry into the box in response to a lock - down signal . the doors 100 and 103 can be unlocked by the appropriate signal transmitted from a central monitoring station or a handheld device . referring to fig8 and 9 , in a further embodiment of the invention , a monitoring unit is housed in a portable housing which includes a low power control unit , a battery and a radio as the major components , connected to each other and other components ( not shown ) in a similar manner to the pervious embodiments discussed above . the portable housing can be a suitcase . the portable unit includes connector 300 for connecting the unit to a solar panel , connector 301 for connecting the unit to sensors and / or controlled devices and connector 302 for connecting the unit to an antenna . the monitoring unit can be used in a number of applications such as in trucks . in trucks the portable monitoring unit can be connected to a fixed low temperature sensor such as model snif - 20 manufactured by winland or a high low temperature sensor such as model winutal manufactured winland , to monitor temperature in refrigeration trucks whereby if the temperature in the truck rises above or below a certain level due to a failure of the climate control system , a trouble signal is sent by the monitoring unit to a central monitoring center to locate the driver . the monitoring unit can also be used to monitor opening of doors in trucks , trains , shipping containers and the like and to send an intrusion signal upon unauthorized entry . it will be understood by those skilled in the art that depending on the container being monitored and the sensors used , the wiring arrangement described in the pervious embodiments will have to be modified accordingly .
a container monitoring system which includes a microprocessor comprising a memory to store data , and a control program executed by said microprocessor , said microprocessor having a stand - by mode and an active mode , a communications means connected to said microprocessor for transmitting data from said microprocessor to a monitoring station , a zone monitoring device on the container connected to said microprocessor in a loop with said microprocessor in said stand - by mode , a power source for supplying power to said microprocessor , communications means and zone monitoring device , wherein upon said microprocessor receiving an input signal from said zone monitoring device , said control program directs said microprocessor to switch to active mode , generate and store in said memory an alarm message corresponding to said input signal from said zone monitoring device , activate said communications means , and transmit said alarm message to a monitoring station .