System and method for synchronizing multiple instrumentation devices

• US 7,240,231 B2
• Filed: 09/30/2002
• Issued: 07/03/2007
• Est. Priority Date: 09/30/2002
• Status: Active Grant

• Current Assignee: National Instruments Corporation (Emerson Electric Company)
• Original Assignee: National Instruments Corporation (Emerson Electric Company)
• Inventors: Conway, Craig M.
• Primary Examiner(s): Perveen; Rehana
• Assistant Examiner(s): Chang; Eric
• Application Number:
  US10/260,597
• Publication Number:
  US 20040064750A1
• Time in Patent Office: 1,737 Days
• Field of Search: 713/401
• US Class Current: 713/401
• CPC Class Codes: G01R 19/2516 Modular arrangements for computer based systems; using personal computers (PC's), e.g. "virtual instruments"
• CPC Class Codes: G01R 31/31907 Modular tester, e.g. controlling and coordinating instruments in a bus based architecture

Abstract

Trigger reception on different instrumentation devices may be synchronized by each instrumentation device generating one or more trigger enable signals and delaying performance of an operation in response to a trigger signal until a transition in a trigger enable signal. An instrumentation system may include several instrumentation devices and a communication medium coupling the instrumentation devices. One of the instrumentation devices may process data in response to a sample clock signal. That instrumentation device may also generate a trigger enable signal and delay performing an operation in response to a trigger signal transmitted via the communication medium until a transition in the trigger enable signal occurs. The trigger enable signal is not the sample clock signal. The trigger enable signal may be synchronized to another trigger enable signal generated by another one of the instrumentation devices.

Claims

1. An instrumentation system comprising:

a plurality of instrumentation devices including a first instrumentation device; and

a communication medium configured to couple the plurality of instrumentation devices;

wherein the first instrumentation device is configured to process data in response to a sample clock signal and to generate a first trigger enable signal, wherein the first instrumentation device is configured to delay performing an operation in response to a trigger signal transmitted to the first instrumentation device via the communication medium until a transition in the first trigger enable signal;

wherein the first instrumentation device includes a delay unit configured to measure a delay between a transition in a reference signal and a transition in the first trigger enable signal;

wherein the first instrumentation device is configured to output data indicative of the delay.

2. The instrumentation system of claim 1, wherein the first instrumentation device is configured to receive data indicative of an amount of compensation, wherein the first instrumentation device is configured to adjust a phase of the first trigger enable signal in response to the data indicative of the amount of compensation.

3. The instrumentation system of claim 2, wherein the first instrumentation device adjusts the phase of the first trigger enable signal by adjusting a current value of a counter.

4. The instrumentation system of claim 3, further including a host computer system configured to receive the data indicative of the delay, to responsively generate the data indicative of an amount of compensation, and to output the data indicative of the amount of compensation.

5. The instrumentation system of claim 1, wherein the first instrumentation device includes an output device, wherein the first instrumentation device is configured to modify a delay of a data path through the output device in response to receiving data indicative of a new delay of the data path through the output device.