這美國(guó)國(guó)家儀器公司PXI-6683H同步模塊有一個(gè)GPS接收器，它控制一個(gè)動(dòng)態(tài)GPS天線并處理來(lái)自衛(wèi)星的RF信號(hào)(1.575 GHz)。然后GPS接收器產(chǎn)生一個(gè)非常精確的每秒脈沖數(shù)(PPS)鎳PXI-6683H用于實(shí)現(xiàn)亞微秒同步。

全球定位系統(tǒng)是由中地球軌道上的20多顆衛(wèi)星組成的，這些衛(wèi)星不斷地向地球發(fā)送信號(hào)。GPS接收器可以區(qū)分這些信號(hào)，并非常精確地確定區(qū)域、速度、方向和時(shí)間。GPS衛(wèi)星裝有原子鐘，它們向地球傳輸?shù)男盘?hào)包含定時(shí)數(shù)據(jù)。這使得GPS框架成為精確的定時(shí)和同步源。

IRIG-IRIG是地球上另一個(gè)重要的函數(shù)鎳PXI-6683H，這是一種用于在儀器之間傳輸精確定時(shí)數(shù)據(jù)以實(shí)現(xiàn)同步的標(biāo)準(zhǔn)。IRIG-B是IRIG標(biāo)準(zhǔn)的具體應(yīng)用，每秒發(fā)送100位信息。在信息中插入一個(gè)秒極限標(biāo)記，接收儀器用它來(lái)使其時(shí)基與IRIG源同步。信息的任何剩余部分都包含數(shù)據(jù)，如一天中的時(shí)間、自年初以來(lái)的天數(shù)、控制功能以及自年初以來(lái)的秒數(shù)，這些數(shù)據(jù)被編碼為直接的二進(jìn)制數(shù)。

這鎳PXI-6683H模塊配備為利用PPS(每秒脈沖數(shù))信號(hào)進(jìn)行同步。任何PFI、PXI觸發(fā)器或PXI星線路都可以配置為PPS輸入端子。

The National Instruments PXI-6683H Synchronization Module has a GPS receiver, which controls a dynamic GPS antenna and processes the RF signals (1.575 GHz) from the satellites. The GPS receiver then creates an extremely exact pulse per second (PPS) that the NI PXI-6683H uses to accomplish sub-microsecond synchronization.  

The GPS is an arrangement of more than 2 dozen satellites in medium Earth orbit that are continually transmitting signals down to earth. GPS receivers can distinguish these signals and determine area, speed, direction and time very precisely. GPS satellites are fitted with atomic clocks, and the signals they transmit to Earth contain timing data. This makes the GPS framework a precise timing and synchronization source.

IRIG-B IRIG is another important function on the NI PXI-6683H, which is a standard used to transmit exact timing data between instruments to accomplish synchronization. IRIG-B is a specific use of the IRIG standard, in which 100 bits of information are sent each second. Inserted in the information is a seconds' limit marker that the accepting instrument uses to synchronize its time-base to the IRIG source. Whatever is left of the information contains data, such as the time of day, days since the start of the year, and alternatively, control functions, and the quantity of seconds since the beginning of the day, encoded as a straight binary number.

The NI PXI-6683H module is equipped for utilizing a PPS (pulse per second) signal for synchronization. Any PFI, PXI_Trigger or PXI_Star line can be configured as the PPS input terminal.