The SIM940 integrates a rubidium oscillator (SRS model PRS10) into the SIM900 platform. It provides stable and reliable performance with an estimated 20 year aging of less than 5 × 10-9 and a demonstrated rubidium oscillator MTBF of over 200,000 hours. The SIM940 is an ideal instrument for calibration and RD laboratories or any application requiring a precision frequency standard..sim940成的振器SRS模型prs10为SIM900平台。它提供了稳定可的估有20年低于5×10-9和明原子振器平均故时200000小时的化性。是校准和RD sim940实室或任何精度的率标准应用的理想仪器There are three 10 MHz outputs with exceptionally low phase noise (-130 dBc/Hz at 10 Hz offset) and one second Allan variance (<2 × 10-11). The SIM940 can be phase-locked to an external 1 pps reference (like GPS), providing Stratum 1 performance. A 1 pps output is also provided that has less than 1 ns of jitter and may be set with 1 ns resolution..有三个10 MHz的出具有常低的相位噪声- 130 dBc / Hz的10 Hz偏置和一个第二伦方差2×10-11。sim940可的相位定到外参1 PPS如GPS提供1层的性。1 PPS出提供了具有小于1纳秒的抖动和可置为1 ns的分率..All functions of the SIM940 can be controlled from a computer via the SIM900 Mainframe. Both RS-232 and GPIB interfaces are supported by the mainframe.sim940的所有功可以控制电主机SIM900。两RS-232和GPIB接口由主机支持。