1460954589-09aa5858-2189-4431-baac-d023d6354db0

1. A digital multimeter comprising:
a. a processor;
b. a selector for choosing measurement criteria, said selector being operatively coupled to said processor;
c. an input operatively coupled to said processor, said input being configured to monitor a device;
d. a backlit display operatively coupled to said processor;
e. a sensor operatively coupled to said digital multimeter proximate said display;
wherein said processor is configured to produce a first data signal containing information about the device being monitored;
said first data signal is modulated to produce an optical indicator on said backlit display that blinks between a first state and a second state that differs from said first state so that said sensor may detect said first and second states;
wherein said sensor is configured to detect said first and said second states and generate a second data signal representative of said first modulated data signal.
2. The digital multimeter of claim 1, wherein said sensor comprises circuitry configured to distinguish said first and second states from ambient light detected at said sensor.
3. The apparatus of claim 1, wherein said sensor is a photovoltaic sensor and said circuitry for distinguishing comprises:
a. an amplifier coupled to an output of said photovoltaic sensor;
b. a comparator coupled to an output of said amplifier; and
c. a signal converter coupled to an output of said comparator and configured to convert said output signal of said comparator into a common interface signal.
4. The apparatus of claim 3, wherein a light emitting diode backlights said display.
5. A remote monitoring apparatus comprising:
a. equipment to be monitored from a remote location, said equipment having,
i. memory;
ii. a processor operatively coupled to said memory;
iii. a light operatively coupled to said processor and said memory;

b. a light sensitive sensor operatively coupled to said equipment and positioned proximate said light;
wherein said processor is configured to produce a first data signal containing information about said equipment;
said first data signal is modulated so that said light blinks between an on state and an off state;
said light sensitive sensor is configured to detect said light on state and said light off state and convert said detected light into a second data signal representative of said first data signal; and
wherein said light sensitive sensor further comprises:
a. a photovoltaic sensor;
b. an amplifier coupled to an output of said photovoltaic sensor;
c. a comparator coupled to an output of said amplifier; and
d. a signal converter coupled to an output of said comparator and configured to convert said output signal of said comparator into a common interface signal.
10. The apparatus of claim 9, wherein said common interface signal is RS232 ASCII.
11. The apparatus of claim 9, wherein said signal converter is a level shifter.
12. The apparatus of claim 9, said light sensitive sensor further comprising a low pass filter intermediate said photovoltaic sensor and at least one input of said amplifier.
13. A remote measuring device comprising:
a. a measuring device having
i. a processor, said processor configured to modulate a first data signal to produce command signals;
ii. memory operatively coupled to said processor,
iii. an input operatively coupled to said processor, said input configured to measure a desired parameter of interest to the user,
iv. a display operatively coupled to said processor and configured to display measurement data, and
v. a backlight operatively coupled to said processor and configured to switch between an on state and an off state in response to said command signals from said processor, and

b. a first light sensitive sensor operatively coupled to said measuring device proximate said backlight,
wherein said sensor is configured to detect said light on state and said light off state and convert said received light into a second data signal representative of said first data signal.
14. The remote measuring device of claim 13, wherein said measuring device is a digital multimeter.
15. The remote measuring device of claim 13, wherein said light is a light emitting diode.
16. The remote measuring device of claim 13, wherein said light sensitive sensor further comprises:
a. a photovoltaic sensor;
b. an amplifier coupled to an output of said photovoltaic sensor;
c. a comparator coupled to an output of said amplifier; and
d. a signal converter coupled to an output of said comparator and configured to convert said output signal of said comparator into a common interface signal.
17. The apparatus of claim 16, wherein said signal converter is a level shifter.
18. The remote measuring device of claim 16, wherein said common interface signal is RS232 ASCII.
19. The remote measuring device of claim 16, said measuring device further comprising a second light sensitive sensor for detecting a second light operatively coupled to said first light sensitive sensor.
20. The remote measuring device of claim 19, wherein said light emitting diode is configured to operate as said second light sensitive sensor.
21. The remote measuring device of claim 20, wherein said remote measuring device operates in a duplex mode by sending and receiving data signals via said light emitting diode.
22. The remote measuring device of claim 19, wherein said second light sensitive sensor is a photovoltaic sensor operatively coupled to said processor.
23. The remote measuring device of claim 13 further comprising a computer coupled to said first light sensitive sensor, said computer being configured to receive said second data signal.
24. The apparatus of claim 16, wherein said signal converter further comprises an RF component for converting said output signal into a wireless format.
25. A method for monitoring a detected electrical parameter using a digital multimeter having a backlight signal modulated in a manner that indicates the electrical parameter, said method comprising the steps of:
positioning a light sensitive sensor proximate said digital multimeter in a position to detect said backlight signal;
receiving at said processor a first data signal representative of said detected electrical parameter;
modulating said first data signal to modulate said backlight signal in a blinking manner, wherein said blinking is representative of said first data signal;
detecting ambient light and light emitted from said backlight at said light sensitive sensor;
converting said emitted light into a second data signal representative of said first data signal.
26. The method of claim 25, wherein said step of converting comprises filtering said ambient light from said emitted light.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. A method for encoding a message communicated between devices, the message having at least one field, the method comprising:
if the field is not optional and contains a value, writing the value to one or more data bytes in a byte buffer; and,
if the field is optional and contains a default value, marking a bit in a reserved byte in the byte buffer to indicate that the field contains a default value.
2. The method of claim 1 and further comprising, if the field is optional and contains a custom value, marking the bit in the reserved byte to indicate that the field contains a custom value and writing the custom value to one or more data bytes in the byte buffer.
3. The method of claim 2 and further comprising inserting the reserved byte into the byte buffer upon first encountering a field in the message that is optional.
4. The method of claim 3 and further comprising, if the reserved byte is full, inserting a next reserved byte into the byte buffer.
5. The method of claim 4 and further comprising maintaining a counter for bits in the reserved byte to determine if the reserved byte is full and incrementing the counter when a bit is marked.
6. The method of claim 5 and further comprising, if the field is an object field, marking a bit in the reserved byte in the byte buffer to indicate that the object field is one of null and non-null.
7. The method of claim 1 wherein the devices include at least one of a wireless device and a data processing system.
8. A system for encoding a message communicated between the system and a remote system over a network, the message having at least one field, the system comprising:
a processor coupled to memory and an interface to the network, and adapted to:
if the field is not optional and contains a value, write the value to one or more data bytes in a byte buffer; and,
if the field is optional and contains a default value, mark a bit in a reserved byte in the byte buffer to indicate that the field contains a default value.
9. The system of claim 8 wherein the processor is further adapted to, if the field is optional and contains a custom value, mark the bit in the reserved byte to indicate that the field contains a custom value and write the custom value to one or more data bytes in the byte buffer.
10. The system of claim 9 wherein the processor is further adapted to insert the reserved byte into the byte buffer upon first encountering a field in the message that is optional.
11. The system of claim 10 wherein the processor is further adapted to, if the reserved byte is full, insert a next reserved byte into the byte buffer.
12. The system of claim 11 wherein the processor is further adapted to maintain a counter for bits in the reserved byte to determine if the reserved byte is full and to increment the counter when a bit is marked.
13. The system of claim 12 wherein the processor is further adapted to, if the field is an object field, mark a bit in the reserved byte in the byte buffer to indicate that the object field is one of null and non-null.
14. The system of claim 8 wherein the system and the remote system include at least one of a wireless device and a data processing system.
15. A computer program product having a computer readable medium tangibly embodying computer executable code for directing a system to encode a message communicated between the system and a remote system over a network, the message having at least one field, the computer program product comprising:
code for, if the field is not optional and contains a value, writing the value to one or more data bytes in a byte buffer; and,
code for, if the field is optional and contains a default value, marking a bit in a reserved byte in the byte buffer to indicate that the field contains a default value.
16. The computer program product of claim 15 and further comprising, code for, if the field is optional and contains a custom value, marking the bit in the reserved byte to indicate that the field contains a custom value and writing the custom value to one or more data bytes in the byte buffer.
17. The computer program product of claim 16 and further comprising code for inserting the reserved byte into the byte buffer upon first encountering a field in the message that is optional.
18. The computer program product of claim 17 and further comprising, code for, if the reserved byte is full, inserting a next reserved byte into the byte buffer.
19. The computer program product of claim 18 and further comprising code for maintaining a counter for bits in the reserved byte to determine if the reserved byte is full and code for incrementing the counter when a bit is marked.
20. The computer program product of claim 19 and further comprising, code for, if the field is an object field, marking a bit in the reserved byte in the byte buffer to indicate that the object field is one of null and non-null.
21. The computer program product of claim 15 wherein the system and the remote system include at least one of a wireless device and a data processing system.