ZYGO ZMI-4004 4-Axis VME64x Measurement Board

ZYGO ZMI-4004 4-Axis VME64x Measurement Board

Product Overview

ZYGO ZMI-4004 4-Axis VME64x Measurement Board is a high-performance 4-axis synchronous measurement board launched by ZYGO company, designed based on the VME64x bus standard. Its core positioning is to provide 4-axis synchronous data acquisition, real-time signal processing, and high-speed data transmission functions for high-end industrial measurement systems such as laser interferometry and precision displacement monitoring. It is the core hardware for achieving multi-dimensional and high-precision measurement. It is specially designed for scenarios that require multi axis collaborative measurement, such as precision machine tool multi axis positioning accuracy calibration, aerospace component multi-dimensional contour detection, etc. It can accurately capture 4 measurement signals and synchronously transmit them to the control system. It is not recommended to use low axis or non VME64x architecture boards as substitutes to avoid inability to meet the requirements of multi axis synchronization and data transmission rate, which may affect measurement accuracy and system compatibility.

Specification parameters

（1） Measure performance parameters

Parameter category/specific indicators

Measure the number of axes

4-axis synchronous measurement, supporting independent channel configuration

Measurement resolution

≤ 0.1 nm (nanometer level accuracy, uniaxial)

Measurement accuracy

± 0.05 µ m (micrometer level error, within the full range)

Sampling rate

Single axis up to 1 MHz, 4-axis synchronous sampling rate up to 500 kHz

Measurement range

0-10 m (can be expanded to a larger range through expansion modules)

Signal input type

Laser interference signal (sine/cosine differential signal), incremental encoder signal (A/B/Z phase)

Signal bandwidth

0-200 kHz (suitable for high-frequency measurement signals)

（2） Bus and interface parameters

Parameter category/specific indicators

Bus standard

Compliant with VME64x specification, supports 32-bit/64 bit data transfer, compatible with VMEbus protocol

Bus transmission rate

Up to 80 MB/s in 64 bit mode and up to 40 MB/s in 32-bit mode

Interface configuration

1 VME64x backplane interface (P1/J1+P2/J2 expansion interface), 4 measurement signal input interfaces (SMA differential interface), 1 RS485 configuration interface (for board parameter setting), 1 synchronous trigger interface (TTL level, supporting multi board synchronization)

Data caching

Onboard 8 MB DDR3 SDRAM cache (2 MB per axis) for temporary storage of measurement data to avoid data loss

（3） Physical and environmental parameters

Parameter category/specific indicators

Size

160 mm x 233 mm (compliant with VME64x standard 6U board size)

Weight

350 g ± 20 g

Working temperature

0 ° C-50 ° C (to be used in a constant temperature environment to ensure accuracy, with temperature fluctuations of ≤± 2 ° C/hour)

Storage temperature

-20°C - 70°C

Relative humidity

20% -80% (no condensation)

Protection level

IP20 (prevents solid foreign objects from entering, suitable for installation inside cabinets)

Heat dissipation method

Conductive heat dissipation (dependent on cabinet heat dissipation system, maximum surface temperature of board ≤ 65 ° C)

（4） Power supply and power consumption parameters

Parameter category/specific indicators

Supply voltage

+5V DC (± 5%),+12V DC (± 10%), -12V DC (± 10%) (requires power supply through VME64x backplane)

Power consumption

≤ 15W during normal operation (4-axis full load sampling), ≤ 3W during standby

Power protection

Equipped with overcurrent protection (overcurrent threshold for each power supply: 5A for+5V, 2A for ± 12V), overvoltage protection (overvoltage threshold for+5V is 6V, overvoltage threshold for ± 12V is 14V)

Performance characteristics

4-axis synchronous high-precision measurement: using a dedicated synchronous clock circuit (clock accuracy ≤ 10 ppm) to ensure that the 4-channel measurement signals have no time difference during sampling, with a synchronization error ≤ 1 ns, and can accurately capture the collaborative displacement changes of multi axis motion equipment, meeting the accuracy calibration requirements of precision machine tools, robots and other multi axis systems.

High speed VME64x bus transmission: Based on the VME64x bus architecture, the transmission rate reaches 80 MB/s in 64 bit mode, which can quickly transmit 4-axis measurement data to the host or control system, avoiding measurement lag caused by data transmission delay, especially suitable for real-time control scenarios.

Multi signal type compatibility: It not only supports laser interference signal input (compatible with ZYGO laser interferometer), but also supports incremental encoder signals, which can flexibly interface with different types of measurement sensors, reduce system integration complexity, and improve the applicability of the board.

Powerful data processing capabilities: Onboard high-performance FPGA chips (field programmable gate arrays) can achieve real-time data filtering (supporting low-pass, high pass, and band-pass filtering) and error compensation (such as linear error and temperature error compensation), reducing the impact of external interference and environmental factors on measurement data and improving data accuracy.

Flexible expansion and synchronization function: Multiple ZMI-4004 cards can be cascaded through the synchronization trigger interface, expanding the number of measurement axes (up to 8 cards can be cascaded, achieving 32 axis measurement); Simultaneously supporting external trigger signal input, it can synchronize with other equipment on the production line (such as motion controllers and vision systems) to meet the requirements of complex measurement processes.

High reliability design: using industrial grade components and undergoing environmental testing such as high temperature, low temperature, and vibration (in compliance with IEC 60068 standard); Optimization of board layout to reduce electromagnetic interference (EMI); Equipped with comprehensive power protection and fault diagnosis functions, it can monitor the working status of the board in real time and reduce equipment failure rates.

Working principle

The working core of ZYGO ZMI-4004 board is "4-axis synchronous signal acquisition - real-time data processing - high-speed bus transmission", the specific process is as follows:

Signal acquisition stage: Four measurement signals (such as laser interference signals and encoder signals) are input into the board through the SMA differential interface. Firstly, they are processed by the signal conditioning circuit (including amplification, filtering, and differential to single ended processing) to convert weak and interfering signals into standard digital signals; Subsequently, under the control of synchronous clock, 4 signals are simultaneously sent to ADC (Analog to Digital Converter, with a resolution of 16 bits) for sampling, ensuring the synchronization of 4-axis data. The sampled data is temporarily stored in the onboard DDR3 SDRAM cache.

Data processing stage: The onboard FPGA chip performs real-time processing on the measurement data stored in the cache, mainly including:

Filtering processing: using preset filtering algorithms (such as Kalman filter, sliding average filter) to remove high-frequency noise and peak interference from the signal;

Error compensation: Based on the stored error compensation table (such as temperature error curve, linear error coefficient), the measurement data is corrected to offset the effects of environmental temperature changes, sensor linear errors, and other factors;

Data format conversion: Convert the processed raw data into a data format that complies with the VME64x bus protocol, in preparation for subsequent transmission.

Data transmission stage: The processed data is transmitted to the host or control system through the VME64x bus interface, following the VME64x protocol specification during the transmission process, and supporting adaptive switching of 32-bit/64 bit data width; If the host sends a data request, the board can directly respond through the bus to achieve real-time data reading; At the same time, the board can also receive parameter setting instructions (such as sampling rate and filtering parameter adjustment) issued by the host through the RS485 configuration interface, and adjust the working status according to the instructions.

Synchronization and expansion phase: When multiple boards need to cascade and expand the number of axes, the motherboard card sends a synchronization clock signal to the slave board through the synchronization trigger interface to ensure that the sampling clocks of all boards are consistent; External trigger signals (such as workstation trigger signals on production lines) can trigger the board to start sampling, achieving synchronous operation with other devices and meeting the needs of multi device collaborative measurement.

Precautions

（1） Installation and commissioning precautions

Board installation: It needs to be installed on the backplane of a 6U cabinet that meets the VME64x standard. Before installation, clean the gold fingers of the backplane interface to remove dust and oxide layers; Ensure alignment with the guide rail and interface when inserting the board to avoid interface damage caused by forced insertion and removal; After installation, check whether the contact between the board and the backplane is tight and there is no looseness.

Environmental control: The installation environment should meet the requirements of constant temperature (0 ° C-50 ° C, temperature fluctuation ≤ ± 2 ° C/hour), constant humidity (20% -80% no condensation), and be away from strong electromagnetic interference sources (such as high-power frequency converters, high-frequency welding machines) and vibration sources (such as punching machines, fans); The cabinet needs to be equipped with an efficient heat dissipation system (such as cooling fans, air conditioning) to ensure that the surface temperature of the board does not exceed 65 ° C, and to avoid high temperatures causing component performance degradation.

Power configuration: The board needs to be provided with+5V,+12V, and -12V power through the VME64x backplane. The power supply must be stable and the voltage fluctuation range must meet the parameter requirements (+5V ± 5%, ± 12V ± 10%); It is recommended to install a voltage regulator module and surge protector at the power input end to prevent damage to the board caused by power fluctuations and surges.

Debugging process:

Pre power on inspection: Confirm that the power supply wiring is correct and there is no reverse polarity or short circuit;

Power on self-test: After connecting the power supply, observe the board indicator lights (power light, work light, fault light). Under normal circumstances, the power light stays on, the work light flashes, and the fault light goes out; If the fault light is on, it is necessary to read the fault code through the RS485 interface and troubleshoot the problem (such as power supply abnormality, interface failure);

Parameter configuration: Set the sampling rate, measurement signal type, filtering parameters, etc. through dedicated software (board configuration tool provided by ZYGO), and save the parameters after configuration is completed;

Accuracy calibration: Connect standard calibration equipment (such as ZYGO standard laser interferometer), calibrate the 4-axis measurement accuracy, record the calibration data. If the accuracy deviation exceeds ± 0.05 µ m, adjust the error compensation parameters until the accuracy meets the standard.

（2） Precautions for use and maintenance

Daily use: It is forbidden to frequently plug and unplug the board during use. If the board needs to be replaced, the power must be cut off first; Avoid modifying the default parameters of the board (such as sampling rate and filtering parameters). If modification is necessary, it should be done through dedicated software. After modification, test the system stability to ensure no data anomalies; Regularly check the status of the board indicator lights. If any malfunction lights up or abnormal flashing of the work lights occur, immediately stop using and troubleshoot.

Regular maintenance:

Monthly: Clean the dust on the surface of the cabinet and board, check the contact between the board and the backplane interface, and tighten loose screws; Read the operating temperature, power supply voltage and other parameters of the board through software to confirm that there are no abnormalities;

Quarterly: Conduct precision calibration on the board, compare measurement data using standard calibration equipment, and if the precision deviation exceeds the allowable range, perform error compensation again; Check the storage performance of onboard cache (DDR3 SDRAM), conduct read and write tests through software to ensure no data loss or errors;

Every year, professional personnel conduct a comprehensive inspection of the board, including visual inspection of components (such as no bulges in capacitors and no discoloration in resistors), integrity inspection of FPGA programs, testing of bus transmission rates, replacement of aging components (such as fans and capacitors), and ensuring stable performance of the board.

Fault handling:

Power failure: If the power light is not on, check whether the power supply is normal and whether the backplane interface is in good contact; If the power light is on but the work light is not on, check if the power voltage is within the allowable range, or read the power fault code through the RS485 interface and replace the faulty power module;

Abnormal measurement data: If the measurement data fluctuates too much or the accuracy deviation exceeds the tolerance, check whether the measurement signal input interface is loose and whether the signal cable is damaged; Re calibrate the accuracy and adjust the filtering parameters; If the abnormality persists, check if the FPGA program is complete and if necessary, re burn the program;

Bus transmission failure: If data cannot be read through the VME64x bus, check if the bus interface is in good contact and if the bus protocol configuration is correct; Use bus testing tools to test the transmission rate and integrity of the bus, and troubleshoot bus faults such as backplane damage and bus conflicts.

（3） Expansion and compatibility considerations

Multi board cascading: When cascading multiple ZMI-4004 boards, it is necessary to ensure that the hardware and firmware versions of all boards are consistent to avoid synchronization errors caused by version differences; The synchronous trigger cable of the master-slave board needs to use shielded cables with a length as consistent as possible (error ≤ 10cm) to reduce synchronization signal delay; After cascading, synchronization accuracy testing should be conducted on all axes to ensure synchronization error ≤ 1 ns

Sensor compatibility: When connecting sensors such as laser interferometers and encoders, it is necessary to confirm that the signal type (such as differential signal, single ended signal) and output frequency of the sensor match the input requirements of the board; Shielded differential cables should be used for signal cables, with cable lengths as short as possible (≤ 10m, and signal amplifiers should be installed for long-distance transmission) to avoid signal attenuation and interference; Before connecting the sensor, check if the power supply of the sensor is normal to avoid damage to the board due to sensor failure.

Software compatibility: The board needs to be used with the official driver and configuration software provided by ZYGO, and the software version needs to be compatible with the firmware version of the board; If using third-party software (such as LabVIEW, MATLAB) for data acquisition and processing, it is necessary to ensure that the third-party software supports the VME64x bus protocol and can correctly parse the data format of the board; After software installation, compatibility testing is required to ensure normal data collection and effective parameter settings.