Data acquisition system

• US 5,062,101 A
• Filed: 07/21/1989
• Issued: 10/29/1991
• Est. Priority Date: 07/21/1989
• Status: Expired due to Term

• Current Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Original Assignee: Johnson Service Company
• Inventors: Dejewski, Michael P.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Marcelo, Melvin
• Application Number:
  US07/384,156
• Time in Patent Office: 830 Days
• Field of Search: 370/4, 318/778, 318/436, 318/808, 318/473, 340/825.15, 455/601, 455/606
• US Class Current: 398/98
• CPC Class Codes: G05B 19/0423 Input/output

Abstract

There is disclosed a data acquisition system for use, for example, in a facility management system, for receiving analog input information, converting the analog input information to multiple-bit digital data, synchronizing the multiple-bit digital data to a serial transfer clock, and restoring the digital data into a bit-parallel format for storage in memory and subsequent digital processing. The data acquisition system includes a plurality of inputs, each input being arranged to receive analog input information. An analog-to-digital converter converts the analog input information at each input to a multiple-bit data word wherein the bits of the data word are in bit-parallel format. A multiplexer couples each of the inputs to the analog-to-digital converter one at a time in succession and a parallel input-serial output register converts the parallel bits to a serial digital bit stream. An optical coupling circuit conveys the serial digital bit stream to a serial-input parallel-output latch by optically processing both the serial digital data stream and transfer enable clock pulses. The latch reconverts the serial digital bit stream to parallel bits of data and holds the parallel bits of data for the direct access, parallel transfer thereof into a memory.

Claims

1. A data acquisition system for use in a facility management system for receiving analog input information, converting said analog input information to multiple-bit digital data, and providing said digital data in a bit-parallel format for direct access storage in memory, said data acquisition system comprising:

an input for receiving said analog input information;

analog to digital conversion means for converting said analog input information to a multiple-bit digital word, the bits of said digital word being in bit-parallel format;

parallel to serial bit means for converting said parallel bits to serial bits;

serial to parallel bit means for receiving and latching said serial bits as re-parallelled bits, said serial to parallel bit means including a clock input, and a transfer enable clock for providing a transfer enable clock signal for each said serial bit to be transferred; and

optical coupler means connecting said parallel to serial bit means to said serial to parallel bit means, including a first input for receiving said serial bits of digital data, for transferring said serial bits provided by said parallel to serial bit means to said serial to parallel bit means and including a second input for receiving said transfer enable clock signal and transferring said transfer enable clock signal to said serial to parallel bit means clock input to provide immunity to electrical noise during said transfer.

2. A system as defined in claim 1 further including a plurality of said inputs for receiving analog input information and multiplexing means for selectively coupling each of said inputs to said analog to digital conversion means one at a time.

3. A system as defined in claim 1 wherein said parallel to serial means comprises a parallel input-serial output circuit.

4. A system as defined in claim 1 wherein said serial to parallel means comprises a serial input-parallel output latch.

5. A facility management data acquisition system comprising:

a plurality of inputs, each said input arranged to receive analog input information;

an analog-to-digital converter for converting the analog input information at each said input to a multiple-bit data word, the bits of said data word being in bit-parallel format;

multiplexing means for coupling each of said inputs to said analog-to-digital converter one at a time in succession;

first means for converting said parallel bits to a serial digital bit stream;

a clock having an output for providing synchronous data transfer enable signals;

second means having a first input for receiving said serial digital bit stream, a second input for receiving said synchronous data transfer enable signals, and means for reconverting said serial digital bit stream to parallel bits of data, said second means also being arranged to hold said parallel bits of data, said second means also being arranged to hold said parallel bits of data for the direct access parallel transfer thereof into a memory; and

an optical coupling circuit having a first input coupled to said first means and a first output coupled to said second means first input for conveying said serial digital bit stream to said second means, and a second input coupled to said clock output and a second output coupled to said second means second input for conveying said synchronous data transfer enable signals to said second means, said optical coupling circuit including an optical coupler for optically processing said serial digital bit stream to render said conveyance immune to electrical noise.

6. A system as defined in claim 5 wherein said multiplexing means comprises a pair of multiplexers.

7. A system as defined in claim 5 wherein said first means comprises a parallel input-serial output circuit.

8. A system as defined in claim 5 wherein said second means comprises a serial input-parallel output latch.

9. A system as defined in claim 5 wherein said first means includes a clock input and wherein said clock output is also coupled to said first means clock input.

10. In a control system of the type which responds to analog information received from a plurality of remote sensors and of the type which includes a digital control means for digitally processing the information received from the remote sensors, a data acquisition system for acquiring said remote sensor analog information and converting said analog information to parallel multiple-bit digital data for use by said digital control means, said data acquisition system comprising:

a plurality of inputs, each said input arranged for receiving analog information from a respective given one of said remote sensors;

an analog-to-digital converter for converting said analog information to digital data and providing said digital data in a multiple-bit parallel format, said analog-to-digital converter having an input;

multiplexing means for selectively coupling each of said inputs to said analog-to-digital converter one at a time;

parallel input-serial output means for converting said multiple-bit parallel digital data to synchronous serial data;

a clock having an output for providing synchronous transfer enable clock signals;

optical coupling means coupled to said parallel input-serial output means and said clock for optically processing said serial data and said synchronous data transfer enable clock signals; and

serial input-parallel output latch means coupled to said optical coupling means for receiving said optically processed digital data and said optically processed synchronous data transfer enable clock signals and providing said data and said clock signals for processing by said digital control means, said data being in a multiple-bit parallel format, said optical coupling means being arranged to transfer said digital data and said synchronous data transfer enable clock signals from said parallel input-serial output means to said latch means during said optical processing to render said digital data and said synchronous data transfer enable clock signals immune to electrical noise.

11. A system as defined in claim 10 wherein each of said inputs has a unique address and wherein said system further comprises control means for conveying to said parallel input-serial output means a parallel bit address corresponding to the input providing said analog information to said analog-to-digital converter.

13. A system as defined in claim 10 wherein said clock output is also coupled to said parallel input-serial output means.

14. A system as defined in claim 13 wherein said clock is arranged to provide a clock signal for each serial bit to be transferred through said optical coupling means to said latch means.

12. A system as defined inc laim 10 wherein said multiplexing means comprises a pair of multiplexers.

15. A facility management data acquisition system comprising:

a plurality of inputs, each said input arranged to receive analog input information;

an analog-to-digital converter for converting the analog input information at each said input to a multiple-bit data word, the bits of said data word being in bit-parallel format;

multiplexing means for coupling each of said inputs to said analog to digital converter one at a time in succession;

control means for generating a multiple-bit input address, said address controlling said multiplexing means;

parallel-to-serial bit means for combining said multiple-bit digital word with said input address and for converting the combined parallel bits to a serial digital bit stream;

a clock having an output for providing synchronous data transfer enable signals;

serial-to-parallel means having a first input for receiving said serial digital bit stream, a second input for receiving said synchronous data transfer enable signals, and means for reconverting said serial digital bit stream to parallel bits of data, said serial-to-parallel means also being arranged to hold said parallel bits of data for the direct access parallel transfer thereof into a memory; and

an optical coupling circuit having a first input coupled to said parallel-to-serial bit means and a first output coupled to said serial-to-parallel means first input for conveying said serial digital bit stream to said serial-to-parallel means, and a second input coupled to said clock output and a second output coupled to serial-to-parallel means second input for conveying said synchronous data transfer enable signals to said serial-to-parallel means, said optical coupling circuit including an optical coupler for optically processing said serial digital bit stream to render said conveyance immune to electrical noise.