EP-4030171-B1 - MAIN MEASUREMENT DEVICE, SECONDARY MEASUREMENT DEVICE, MEASUREMENT SYSTEM AND METHOD

EP4030171B1EP 4030171 B1EP4030171 B1EP 4030171B1EP-4030171-B1

Inventors

ZIEGLER, ANDREAS
SCHLAGER, DETLEF
NAUMANN, JENS
PETZSCH, SEBASTIAN
KUHWALD, THOMAS
SCHAEFER, ANDREW
GRIMM, MICHAEL

Dates

Publication Date: 20260506
Application Date: 20210118

Claims (9)

Main measurement device (100, 300) for simultaneously measuring signals with at least one secondary measurement device (220, 320), the main measurement device (100, 300) comprising: a reference signal output port (101, 222, 301) configured to couple to the at least one secondary measurement device (220, 320); a reference signal generator (102, 223) coupled to the reference signal output port (101, 222, 301) and configured to generate a reference signal (103, 224); a measurement port (105, 225) configured to receive a signal to be measured; a trigger output port (111, 311) configured to couple to a trigger input port (231, 331) of the at least one secondary measurement device (220, 320) and to output a trigger signal; and a controllably switchable internal signal path (106, 226) configured to selectively couple the reference signal generator (102, 223) internally with the measurement port (105, 225); and comprising a device controller (110, 230) coupled to the reference signal generator (102, 223) and the switchable internal signal path (106, 226), wherein the device controller (110, 230) is configured to perform in a calibration operation mode a calibration of the synchronization between the main measurement device (100, 300) and the at least one secondary measurement device (220, 320) by: controlling the reference signal generator (102, 223) to output the reference signal (103, 224) via the reference signal output port (101, 222, 301) to the at least one secondary measurement device (220, 320), controlling the switchable internal signal path (106, 226) to couple the reference signal generator (102, 223) with the measurement port (105, 225), controlling the measurement port (105, 225) to measure the reference signal (103, 224) provided by the reference signal generator (102, 223) via the switchable internal signal path (106, 226), and generating a main timestamp for the measured reference signal (103, 224) and outputting a trigger signal via the trigger output port (111, 311) at the same time; and the main measurement device (100, 300) further comprising a communication interface (112, 312, 232, 332) for communicating with the at least one secondary measurement device (220, 320), wherein the device controller (110, 230) is further configured to transmit the reference signal (103, 224) as measured by the measurement port (105, 225) with the main timestamp via the communication interface (112, 312, 232, 332) to the at least one secondary measurement device (220, 320), and to receive the skew time via the communication interface (112, 312, 232, 332) from the at least one secondary measurement device (220, 320).
Main measurement device (100, 300) according to claim 1, wherein the device controller (110, 230) is configured to synchronize measurement data in a measurement operation mode by: controlling the measurement port (105, 225) to measure an external signal to be measured; generating upon occurrence of a trigger condition in the external signal a main timestamp and a trigger signal, and outputting the trigger signal via a trigger output port (111, 311) of the main measurement device (100, 300); and receiving via the communication interface (112, 312, 232, 332) measurement data from the at least one secondary measurement device (220, 320), the measurement data including a secondary measurement timestamp and timely shifting the received measurement data based on the secondary measurement timestamp and the skew time, or providing the main timestamp via the communication interface (112, 312, 232, 332) to the at least one secondary measurement device (220, 320).
Secondary measurement device (220, 320) for simultaneously measuring signals with a main measurement device (100, 300), the secondary measurement device (220, 320) comprising: a reference signal input port (104, 221, 321) configured to couple to a reference signal output port (101, 222, 301) of the main measurement device (100, 300); a measurement port (105, 225) configured to receive a signal to be measured; a trigger input port (231, 331) configured to receive an external trigger signal, especially from the main measurement device (100, 300); a controllably switchable internal signal path (106, 226) configured to selectively couple the reference signal input port (104, 221, 321) internally with the measurement port (105, 225) a device controller (110, 230) coupled to the switchable internal signal path (106, 226), wherein the device controller (110, 230) is configured to perform in a calibration operation mode a calibration of the synchronization between the main measurement device (100, 300) and the secondary measurement device (220, 320) by: controlling the switchable internal signal path (106, 226) to couple the reference signal input port (104, 221, 321) with the measurement port (105, 225), controlling the measurement port (105, 225) to measure the reference signal (103, 224) provided by the reference signal input port (104, 221, 321) via the switchable internal signal path (106, 226), and generating a secondary timestamp for the measured reference signal (103, 224) upon receipt of a trigger signal via the trigger input port (231, 331); and the secondary measurement device (220, 320) further comprising a communication interface (112, 312, 232, 332) for communicating with the main measurement device (100, 300), wherein the device controller (110, 230) is configured to transmit the reference signal (103, 224) as measured by the measurement port (105, 225) with the secondary timestamp via the communication interface (112, 312, 232, 332) to the main measurement device (100, 300), and to receive the skew time via the communication interface (112, 312, 232, 332) from the main measurement device (100, 300).
Secondary measurement device (220, 320) according to claim 3, wherein the device controller (110, 230) is configured to synchronize measurement data in a measurement operation mode by: controlling the measurement port (105, 225) to measure an external signal, generating a measurement timestamp upon reception of an external trigger signal via a trigger input port (231, 331) of the secondary measurement device (220, 320); receiving a main timestamp via the communication interface (112, 312, 232, 332); and timely shifting measurement data of the measured external signal based on the measurement timestamp, the main timestamp and the skew time.
Measurement system (340) comprising: a main measurement device (100, 300) according to any one of the main measurement device (100, 300) related claims 1 to 2; and at least one secondary measurement device (220, 320) according to any one of the secondary measurement device (220, 320) related claims 3 to 4; wherein the communication interface (112, 312, 232, 332) of the main measurement device (100, 300) is coupled to the communication interfaces (112, 312, 232, 332) of the at least one secondary measurement device (220, 320); wherein the reference signal output port (101, 222, 301) of the main measurement device (100, 300) is coupled to the reference signal input port (104, 221, 321) of the at least one secondary measurement device (220, 320); and wherein the trigger output port (111, 311) of the main measurement device (100, 300) is coupled to the trigger input port (231, 331) of the at least one secondary measurement device (220, 320).
Method for synchronizing simultaneous measurement of signals with a main measurement device (100, 300) and at least one secondary measurement device (220, 320), the main measurement device (100, 300) comprising a reference signal output port (101, 222, 301), a measurement port (105, 225), a trigger output port (111, 311), and a communication interface (112, 312, 232, 332), and the at least one secondary measurement device (220, 320) comprising a reference signal input port (104, 221, 321) coupled to the reference signal output port (101, 222, 301), a measurement port (105, 225), a trigger input port (231, 331) coupled to the trigger output port (111, 311), and a communication interface (112, 312, 232, 332) coupled to the communication interface (112, 312, 232, 332) of the main measurement device (100, 300), the method comprising: outputting (S1) a reference signal (103, 224) generated by a reference signal generator (102, 223) in the main measurement device (100, 300) via the reference signal output port (101, 222, 301) of the main measurement device (100, 300) to the reference signal input port of the at least one secondary measurement device (220, 320); internally (S2) coupling the reference signal generator (102, 223) with the measurement port (105, 225) of the main measurement device (100, 300); internally (S3) coupling the reference signal input port (104, 221, 321) of the at least one secondary measurement device (220, 320) with the measurement port (105, 225) of the at least one secondary measurement device (220, 320); measuring (S4) the reference signal (103, 224) with the measurement port (105, 225) of the main measurement device (100, 300); measuring (S5) the reference signal (103, 224) with the measurement port (105, 225) of the at least one secondary measurement device (220, 320); generating (S6) a main timestamp for the measured reference signal (103, 224) in the main measurement device (100, 300); outputting (S7) a trigger signal via the trigger output port (111, 311) of the main measurement device (100, 300) concurrently with generating the main timestamp; transmitting the generated reference signal (103, 224) with the main timestamp from the main measurement device (100, 300) to the at least one secondary measurement device (220, 320); generating (S8) a secondary timestamp for the measured reference signal (103, 224) in the at least one secondary measurement device (220, 320) upon receipt of the trigger signal; receiving the skew time from the at least one secondary measurement device (220, 320) at the main measurement device (100, 300); and determining (S9) a skew time based on the data measured in the main measurement device (100, 300) and the main timestamp and the data measured in the at least one secondary measurement device (220, 320) and the respective secondary timestamp.
Method according to claim 6, wherein determining the skew time comprises: receiving in the main measurement device (100, 300) via the communication interface (112, 312, 232, 332) the reference signal (103, 224) as measured by the at least one secondary measurement device (220, 320) together with the secondary timestamp generated by the at least one secondary measurement device (220, 320) upon receipt of the trigger signal, calculating a coarse timing variation between the main measurement device (100, 300) and the at least one secondary measurement device (220, 320) based on the difference between the secondary timestamp and the main timestamp, calculating a granular timing variation between the main measurement device (100, 300) and the at least one secondary measurement device (220, 320) based on the phase difference between the phase of the reference signal (103, 224) as measured by the measurement port (105, 225) of the main measurement device (100, 300) at the main timestamp and as measured by the measurement port (105, 225) the at least one secondary measurement device (220, 320) at the secondary timestamp, and calculating the skew time as the sum of the coarse timing variation and the granular timing variation; or wherein determining the skew time comprises: receiving in the secondary measurement device (220, 320) via the communication interface (112, 312, 232, 332) the reference signal (103, 224) as measured by the main measurement device (100, 300) together with a main timestamp generated by the main measurement device (100, 300) upon generation of the trigger signal, calculating a coarse timing variation between the main measurement device (100, 300) and the secondary measurement device (220, 320) based on the difference between the main timestamp and the secondary timestamp, calculating a granular timing variation between the main measurement device (100, 300) and the secondary measurement device (220, 320) based on the phase difference between the phase of the reference signal (103, 224) as measured by the measurement port (105, 225) of the at least one secondary measurement device (220, 320) at the secondary timestamp and as measured by the measurement port (105, 225) of the main measurement device (100, 300) at the main timestamp, and calculating the skew time as the sum of the coarse timing variation and the granular timing variation.
Method according to claim 7, wherein determining the skew time comprises additionally determining the skew time based on a cable runtime of a cable (341, 342) used to couple the main measurement device (100, 300) to the at least one secondary measurement device (220, 320) and/or internal signal runtimes of the main measurement device (100, 300) and/or the secondary measurement device (220, 320).
Method according to any one of the preceding method-based claims, comprising synchronizing measurement data by: measuring a first external signal to be measured in the main measurement device (100, 300); measuring a second external signal to be measured in the at least one secondary measurement device (220, 320); generating in the main measurement device (100, 300) upon occurrence of a trigger condition in the external signal a main timestamp and a trigger signal, outputting the trigger signal to the at least one secondary measurement device (220, 320) concurrently with generating the main timestamp; generating in the at least one secondary measurement device (220, 320) a secondary timestamp upon reception of the trigger signal; and timely shifting measurement data of the measured second external signal based on the main timestamp and the secondary timestamp and the skew time by: receiving in the main measurement device (100, 300) measurement data from the at least one secondary measurement device (220, 320) including the secondary measurement timestamp and in the main measurement device (100, 300) shifting the received measurement data based on the secondary measurement timestamp and the skew time; or providing the main timestamp via the communication interface (112, 312, 232, 332) to the at least one secondary measurement device (220, 320), and in the at least one secondary measurement device (220, 320) shifting measurement data of the measured external signal based on the secondary timestamp, the main timestamp and the skew time.

Description

TECHNICAL FIELD The disclosure relates to a main measurement device, a secondary measurement device, a measurement system and a respective method. BACKGROUND Although applicable to any electronic device with signal inputs, the present disclosure will mainly be described in conjunction with measurement devices. During the development of modern electronic devices, a plurality of measurement tasks are usually performed. For example, signals in a circuit may be measured to verify if a circuit is operating correctly. With increasing complexity of the electronic devices more signals may need to be measured. To this end, measurement devices, like oscilloscopes may either be provided with more signal inputs, or multiple measurement devices may be coupled together to use the signal inputs of the coupled devices. Coupling multiple measurement devices, however, usually requires complex coupling and synchronization between the measurement devices. Document US 2010 / 0 121 597 A1 discloses a measurement system with two measurement devices and an external switching device, wherein the external switching device is capable of coupling a reference signal or the signal to be measured to the measurement inputs of the measurement devices. Accordingly, there is a need for simplifying the connection of multiple measurement devices. SUMMARY The above stated problem is solved by the features of the independent claims. It is understood, that independent claims of a claim category may be formed in analogy to the dependent claims of another claim category. The present disclosure is based on the finding that synchronizing multiple measurement devices usually is a complex task that requires additional synchronization hardware, like additional signal sources or the like. The present disclosure therefore tries to simplify the synchronization of multiple measurement devices like e.g., oscilloscopes, and the simultaneous measurement of signals that are to be measured. To this end, the present disclosure provides the main measurement device and secondary measurement devices, which may be combined in a respective measurement system. It is understood, that in a measurement system according to the present disclosure, any number of secondary measurement devices may be combined with a main measurement device. The main measurement device comprises a reference signal generator that generates a reference signal. The reference signal serves as the base signal for the synchronization of multiple measurement devices. The reference signal may e.g., be a signal with a predetermined frequency, like 10 MHz, or the like. In the secondary measurement devices, the reference signal may mainly serve for synchronizing their internal reference signal generators to run with the same speed as the reference signal generator of the main measurement device. The reference signal generators may comprise e.g., a phase-locked loop or PPL, that may synchronize with a received reference signal. For a stand-alone operation, in addition, a clock source like e.g., a quartz oscillator with the required frequency, may be provided. However, synchronizing multiple measurement devices only via the reference signal does not allow to provide highly synchronized measurement devices, because internal runtimes and tolerances of electronic elements may still introduce time variations in the single measurement devices. The present invention therefore provides the main measurement device and the secondary measurement devices with the ability to highly synchronize their operation. To this end, the switchable internal signal path is provided in the main measurement device, as well as in the secondary measurement device. In the main measurement device, the switchable internal signal path may selectively couple the reference signal generator with the measurement port. Therefore, the reference signal as generated in the reference signal generator of the main measurement device may be measured by the measurement port of the measurement device. At the same time the reference signal is output via the reference signal output port to the secondary measurement devices. In the secondary measurement devices, the switchable internal signal path may selectively couple the reference signal input port with the measurement port. Therefore, in the secondary measurement devices, the reference signal as generated by the reference signal generator of the main measurement device may be measured. It is understood, that the measurement ports of the main measurement device and the secondary measurement devices may be the measurement ports as provided by the respective measurement device for performing their intended measurement tasks. Such measurement ports may in embodiments comprise any combination of external hardware connectors, amplifiers, attenuators, analog-to-digital converters, a trigger system and an acquisition memory, but are not limited to these elements. In addition, the main measurement device and t