System level health monitoring in test systems
View Patent ↗To perform system level physical connectivity monitoring measurements, a test signal may be generated in an instrument and transmitted down a signal path extending from the instrument to a device. In a static state (high or low), the test signal generator may produce a specified AC impedance at the point where the signal path connects to the instrument for a designated back termination. A response signal resulting from the test signal may be acquired and used to obtain an impedance value and/or reflection coefficient value representative of the signal path and an additional signal path extending from the source of the test signal to the signal path. The measured response may be compared to an expected response to determine a condition of any component(s) in the signal path and/or in the additional signal path. The expected response may be represented by masks (low and high) created during automated test development.
1. A method for monitoring physical connectivity in a system, the method comprising:
generating, by a pulse generator in an instrument, a test signal down a signal path extending from the instrument to a device;
acquiring, by data acquisition circuitry, a response signal generated in response to the test signal in the signal path and an additional signal path extending from a source of the test signal to the signal path;
obtaining, based at least on the response signal, a measured response representative of the signal path and the additional signal path;
comparing the measured response with an expected response; and
determining a condition of the signal path and the additional signal path based on said comparing.
2. The method of claim 1 , further comprising:
obtaining, based on the measured response, a parameter value associated with the signal path and the additional signal path; and
obtaining, based on the expected response, a parameter value associated with the signal path and the additional signal path;
wherein said comparing comprises comparing the parameter value with the expected parameter value.
3. The method of claim 1 , wherein when in a static state, the pulse generator produces a specified alternating current (AC) impedance for a designated back termination at a connector of the instrument from where the signal path extends to the device.
4. The method of claim 1 , wherein said generating the test signal comprises switchably coupling the pulse generator into the additional signal path.
5. The method of claim 1 , wherein the data acquisition circuitry comprises an analog-to-digital converter, wherein said obtaining the measured response comprises digitizing the response signal.
6. The method of claim 1 , wherein the signal path comprises cabling connected between the instrument and the device.
7. The method of claim 1 , wherein the pulse generator is comprised in one of:
an input stage of the instrument, wherein the signal path extends from an input connection of the input stage to the device; or
an output stage of the instrument, wherein the signal path extends from an output connection of the output stage to the device.
8. The method of claim 1 , further comprising:
switchably coupling the pulse generator into the signal path prior to said generating the test signal.
9. An instrument comprising:
a test circuit configured to generate a test signal down a signal path that couples the instrument to a device; and
a data acquisition circuit configured to:
acquire a response signal generated in response to the test signal in the signal path and an additional signal path extending from a source of the test signal to the signal path;
obtain, based at least on the response signal, a measured response representative of the signal path and the additional signal path;
compare the measured response with an expected response; and
determine a condition of the signal path and the additional signal path based on results of the comparison.
10. The instrument of claim 9 , wherein the data acquisition circuit is further configured to:
obtain, based on the measured response, a parameter value associated with the signal path and the additional signal path;
obtain, based on the expected response, an expected parameter value associated with the signal path and the additional signal path; and
compare the parameter value with the expected parameter value to determine the condition of the signal path and the additional signal path.
11. The instrument of claim 9 ;
wherein the parameter value provides an indication of one of:
a measured impedance representative of the signal path;
a measured return voltage representative of the signal path; or
a measured reflection coefficient representative of the signal path; and
wherein the expected parameter value provides an indication of one of:
an expected impedance representative of the signal path;
an expected return voltage representative of the signal path; or
an expected reflection coefficient representative of the signal path.
12. The instrument of claim 9 , wherein the test circuit comprises a pulse generator configured to toggle from a low state to a high state to generate the test signal, wherein the test signal comprises a plurality of pulses.
13. The instrument of claim 12 further comprising:
a switching circuit configured to switchably couple the pulse generator into the signal path.
14. The instrument of claim 9 , wherein the data acquisition circuit is further configured to:
sample the response signal to obtain a plurality of sample values; and
obtain the measured response from the plurality of sample values.
15. A test circuit for monitoring physical connectivity in a system, the test circuit comprising:
a signal-generating circuit configured to generate a test signal;
a switching circuit configured to switchably couple the signal-generating circuit into a signal path extending between an instrument and a device; and
a data acquisition circuit configured to:
acquire a response signal generated in response to the test signal in the signal path and an additional signal path extending from a source of the test signal to the signal path;
obtain, based at least on the response signal, a measured response representative of the signal path and the additional signal path;
compare the measured response with an expected response; and
determine a condition of the signal path and the additional signal path based on results of the comparison.
16. The test circuit of claim 15 , wherein the data acquisition circuit is further configured to:
obtain, based on the measured response, a parameter value associated with the signal path and the additional signal path;
obtain, based on the expected response, an expected parameter value associated with the signal path and the additional signal path; and
compare the parameter value with the expected parameter value to determine the condition of the signal path and the additional signal path.
17. The test circuit of claim 15 ;
wherein the parameter value provides an indication of one of:
a measured impedance representative of the signal path;
a measured return voltage representative of the signal path; or
a measured reflection coefficient representative of the signal path; and
wherein the expected parameter value provides an indication of one of:
an expected impedance representative of the signal path;
an expected return voltage representative of the signal path; or
an expected reflection coefficient representative of the signal path.
18. The test circuit of claim 17 , wherein the signal path comprises cabling connected between the instrument and the device.
19. The test circuit of claim 15 , wherein the signal-generating circuit comprises a pulse generator configured to toggle from a low state to a high state to generate the test signal, wherein the test signal comprises a plurality of pulses.
20. The test circuit of claim 15 , wherein the data acquisition circuit is further configured to:
sample the response signal to obtain a plurality of sample values; and
obtain the measured response from the plurality of sample values.