[0014] Embodiment 1: Combining figure 1 As shown, the technical solution of the present embodiment is described, and its method steps are:
[0015] Step 1: Motion control card master card 1, multiple motion control card slave cards 2, multi-channel laser interferometer data acquisition card 3 and multi-channel grating data acquisition card 4 are all connected to VME bus 7; The laser interferometer data acquisition card 3 updates the collected data sent by multiple laser interferometers 5 at a frequency of 10MHz, and assigns these data to different address codes and stores them in the RAM of the multi-channel laser interferometer data acquisition card 3 ; The multi-channel raster data acquisition card 4 updates the collected data sent by the multiple raster sensors 6 at a frequency of 10MHz, and assigns these data to different address codes and stores them in the RAM of the multi-channel raster data acquisition card 4;
[0016] Step 2: The DSP module in the motion control card master card 1 sends a reading request every 200us, and the reading request is sent to the FPGA module in the motion control card master card 1 and multiple motion control card slave cards 2 synchronously respectively. In the FPGA module of The reading module subroutine in it; all motion control cards execute the reading module subroutine after receiving the above-mentioned reading request from the FPGA module in the card 2;
[0017] Step 3: The subroutine of the grating data address code sending module or the subroutine of the laser interferometer data address code sending module sets the data latch signal on the VME bus 7 to high through the CPLD module in the main card 1 of the motion control card, and makes the multi-channel data latch signal high. The data in the RAM of the laser interferometer data acquisition card 3 and the data in the RAM of the multi-channel grating data acquisition card 4 are latched and will not be updated; at the same time, all motion control cards pass the motion from the reading module subroutine in card 2 The CPLD module in the control card slave card 2 detects whether the address line address on the VME bus 7 is updated; the reading module subroutine in the main card 1 of the motion control card detects the Whether the address line address is updated;
[0018] Step 4: The subroutine of the grating data address code sending module or the subroutine of the laser interferometer data address code sending module sends the data to the multi-channel laser interferometer data acquisition card 3 and the multi-channel through the CPLD module in the main card 1 of the motion control card and the VME bus 7 The grating data acquisition card 4 sends the address code of the data to be read, and the multi-channel laser interferometer data acquisition card 3 and the multi-channel grating data acquisition card 4 will automatically detect whether the corresponding address code data is stored in their own RAM, such as If yes, send this data and the corresponding address code to the VME bus 7;
[0019] Step 5: When all motion control cards detect the update of the address line address on VME bus 7 from the CPLD module in card 2 through the motion control card from the reading module subroutine in card 2, then delay a few clocks , then the reading module subroutine sets the read enable signal low, and the control FPGA module reads and writes the data on the VME bus 7 into its own RAM through the CPLD module; After the program detects that the address line address on the VME bus 7 is updated through the CPLD module in the main card 1 of the motion control card, it delays the time of several clocks, and then the reading module subroutine sets the read enable signal low, Control the FPGA module to read and write the data on the VME bus 7 into its own RAM through the CPLD module, and generate a reading completion mark in the subroutine of the raster data address encoding sending module or the subroutine of the laser interferometer data address encoding sending module;
[0020] Step 6: Repeat step 4 and step 5, until all the data in the RAM of the multi-channel laser interferometer data acquisition card 3 and all the data in the RAM of the multi-channel grating data acquisition card 4 are read in turn; Then the subroutine of the grating data address code sending module or the subroutine of the laser interferometer data address code sending module sets the data latch signal on the VME bus 7 low through the CPLD module in the main card 1 of the motion control card, so that the multi-channel laser interferometer The data in the RAM in the data acquisition card 3 and the data in the RAM in the multi-channel raster data acquisition card 4 are unlocked and stored and continue to be updated;
[0021] Step 7: The data in the RAM of the CPLD module in the main card 1 of the motion control card is transferred to the DSP module in the main card 1 of the motion control card; all motion control cards are transferred from the RAM of the CPLD module in the card 2 to the In their respective DSP modules; realize multi-board synchronization and sequential reading of multi-channel sensor data.
[0022] The address output of the grating data address coding sending module subprogram or the laser interferometer data address coding sending module subprogram is incrementally switched according to the time sequence protocol, and the output is in a high-impedance state at other times. The output high impedance state is realized without occupying the address line.
[0023]Working principle: the realization of the method of the present invention requires the support of the following software and hardware parts, and the hardware includes a VME chassis, a motion control card, a laser interferometer, an interferometer data acquisition card, a grating, a grating data acquisition card, a computer and a corresponding signal transmission line, The software includes CCStudio, a software developed based on DSP, and QuartusII, a software developed based on FPGA.
[0024] The VME chassis provides a chassis with a 21-slot backplane for 6UVME cards, which can accommodate 21 boards with VME interfaces. The VME pins corresponding to each slot except the first are connected to each other for each card. Intercommunication between VME buses;
[0025] The motion control card uses the DSP chip with the model TMS320C6414 as the algorithm processing module, the FPGA with the model EP2S60F102014N as the main signal processing module, the CPLD chip as the level conversion module, and the DSP module through its own external storage expansion interface EMIF and FPGA module communicate, and multiple boards exchange data through the VME bus;
[0026] Both the laser interferometer and the grating are length measurement sensors, and in the present invention, both are used to obtain the position of the control object;
[0027] The interferometer data acquisition card and the grating data acquisition card are respectively responsible for latching the data of the connected multi-channel interferometer or grating and placing the data of a corresponding sensor on the data line according to the address on the address line for the motion control card to read. Pick. The interferometer data acquisition card can acquire 18 channels of interferometer data, and the grating data acquisition card can acquire 12 channels of grating data. The two acquisition cards communicate with the motion control card through the VME bus, and the address lines and data lines used are the same, which are defined in the user-defined area of the VME bus P2 interface.
