Synchronization of receiver units over a control area network bus

• US 9,641,267 B2
• Filed: 06/10/2014
• Issued: 05/02/2017
• Est. Priority Date: 06/10/2014
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Quintero, Alberto, Jin, Guosheng, Zhang, Xiaohong, Lie, Joni Polill, Schaecher, William Joseph
• Primary Examiner(s): Perez, James M
• Application Number:
  US14/435,116
• Publication Number:
  US 20160277136A1
• Time in Patent Office: 1,057 Days
• Field of Search: 375219-223, 375259-376, 702 85-199
• CPC Class Codes: G01V 1/26 Reference-signal-transmitting devices, e.g. indicating moment of firing of shot
• CPC Class Codes: G01V 1/40 specially adapted for well-logging
• CPC Class Codes: H04J 3/0658 Clock or time synchronisation among packet nodes
• CPC Class Codes: H04J 3/10 Arrangements for reducing cross-talk between channels
• CPC Class Codes: H04J 3/12 Arrangements providing for calling or supervisory signals
• CPC Class Codes: H04L 12/40 Bus networks
• CPC Class Codes: H04L 2012/40215 Controller Area Network CAN
• CPC Class Codes: H04L 7/0087 Preprocessing of received signal for synchronisation, e.g. by code conversion, pulse generation or edge detection
• CPC Class Codes: H04Q 2209/30 using a wired architecture
• CPC Class Codes: H04Q 2209/845 where the measuring is synchronized between sensing devices
• CPC Class Codes: H04Q 9/04 Arrangements for synchronous operation

Abstract

In a logging system (100), multiple receiver units (106) are synchronized over a control area network (CAN) bus (110) without use of separate differential lines. A ready for synchronization command is received over the CAN bus (110). In response to receiving the ready for synchronization command, a start synchronization interrupt is enabled. A start synchronization command is then received over the CAN bus (110). In response to receiving the start synchronization command, the start synchronization interrupt is triggered for capturing formation signals which are produced responsive to excitation signals from a transmitter unit (104).

Claims

1. A method of synchronizing a plurality of receiver units over a control area network (CAN) bus, the method comprising:

receiving, over the CAN bus, a ready for synchronization command;

enabling a start synchronization interrupt in response to receiving the ready for synchronization command;

receiving, over the CAN bus, a start synchronization command; and

in response to receiving the start synchronization command, triggering the start synchronization interrupt for capturing a formation signal.

2. The method of claim 1, further comprising:

initializing a timer with a fixed time value and starting the timer in response to receiving the start synchronization command; and

capturing the formation signals upon expiration of the timer.

3. The method of claim 1, further comprising:

reading a predetermined phase delay associated with a frequency of the formation signal; and

delaying by the predetermined phase delay prior to capturing the formation signals.

4. The method of claim 1, wherein the formation signals are produced responsive to excitation signals communicated from a transmitter unit.

5. The method of claim 1, wherein the enabling of the start synchronization interrupt further comprises disabling all other interrupts in response to receiving the ready for synchronization command.

6. The method of claim 1, wherein the enabling of the start synchronization interrupt further comprises enabling the synchronization interrupt as the highest priority interrupt over other interrupts.

7. The method of claim 1, further comprising:

ceasing the capturing of the formation signals; and

repeating the receiving of the ready for synchronization command, enabling of the start synchronization interrupt, receiving of the start synchronization command, and triggering of the start synchronization interrupt for capturing the logging signals.

10. The receiver unit of claim 1, wherein the CPU is further programmed with instructions to:

read a predetermined phase delay associated with a frequency of the formation signal and delay by the predetermined phase delay prior to capturing the formation signals.

8. A receiver unit, comprising:

a central processing unit (CPU);

memory coupled to the CPU; and

a control area network (CAN) bus interface coupled to the CPU,

wherein the CPU is programmed with instructions, stored in the memory, to;

receive, via the CAN bus interface, a ready for synchronization command;

enable a start synchronization interrupt in response to receiving the ready for synchronization command; and

receive, via the CAN bus interface, a start synchronization command; and

wherein the start synchronization interrupt is enabled to trigger in response to receiving the start synchronization command for use in capturing a formation signal.

9. The receiver unit of claim 8, wherein the CPU is further programmed with instructions to:

initialize a timer with a fixed time value and start the timer in response to receiving the start synchronization command; and

capture the formation signals upon expiration of the timer.

11. The receiver unit of claim 8, wherein the formation signals are produced responsive to excitation signals communicated from a transmitter unit.

12. The receiver unit of claim 8, wherein the CPU is further programmed with instructions to enable the start synchronization interrupt by further disabling all other interrupts in response to receiving the ready for synchronization command.

13. The receiver unit of claim 8, wherein the CPU is further programmed with instructions to enable the start synchronization interrupt by further enabling the synchronization interrupt as the highest priority interrupt over other interrupts.

14. The receiver unit of claim 8, wherein the CPU is a microprocessor.

15. A logging system, comprising:

a master control unit;

a plurality of receiver units coupled to each other and to the master control unit over a control area network (CAN) bus ; and

a transmitter unit coupled to the master control unit , the transmitter unit being configured to transmit excitation signals to a formation,

wherein each receiver unit is configured to;

receive, from the master control unit over the CAN bus, a ready for synchronization command;

enable a start synchronization interrupt in response to receiving the ready for synchronization command;

receive, from the master control unit over the CAN bus, a start synchronization command; and

in response to receiving the start synchronization command, trigger the start synchronization interrupt for capturing formation signals which are produced responsive to the excitation signals from the transmitter unit.

16. The logging system of claim 15, wherein each receiver unit is further configured to:

initialize a timer with a fixed time value and start the timer in response to receiving the start synchronization command; and

capture the formation signals upon expiration of the timer.

17. The logging system of claim 15, wherein each receiver unit is further configured to:

read a predetermined phase delay associated with a frequency of the formation signal and delay by the predetermined phase delay prior to capturing the formation signals.

18. The logging system of claim 15, wherein each receiver unit is configured to enable the start synchronization interrupt and disable all other interrupts in response to receiving the ready for synchronization command.

19. The logging system of claim 15, wherein each receiver unit is configured to enable the start synchronization interrupt by further enabling the synchronization interrupt as the highest priority interrupt over all other interrupts.

20. A method for use by a master control unit for synchronizing a plurality of receiver units over a control area network (CAN) bus, the method comprising:

transmitting, over the CAN bus to a receiver unit, a ready for synchronization command;

transmitting, over the CAN bus to the receiver unit , a start synchronization command following the ready for synchronization command; and

in response to the start synchronization command, enabling excitation signals from a transmitter unit for the receiver unit to start capturing a formation signal.

21. The method of claim 20, wherein each receiver unit is further configured to:

initialize a timer with a fixed time value and start the timer in response to receiving the start synchronization command; and

capture the formation signals upon expiration of the timer.

22. The method of claim 20, wherein each receiver unit is further configured to:

read a predetermined phase delay associated with a frequency of the formation signal and delay by the predetermined phase delay prior to capturing the formation signals.

23. The method of claim 20, wherein each receiver unit is further configured to:

enable a start synchronization interrupt in response to receiving the ready for synchronization command;

in response to receiving the start synchronization command, trigger the start synchronization interrupt for capturing formation signals which are produced responsive to the excitation signals from the transmitter unit.