CMD55产品特点：
 ·是测量GSM及GSM1800移动电话的紧缩式单元
 ·通过RS232，IEC/IEEE远控
 ·前面板有多功能连接器
 ·话音编码器/解码器可被集成
 ·可选择安培表和伏特表
 ·高敏感度二级RF输入
 ·可改进为GSM、GSM1800及GSM1900测试
  综合测试仪系列：8960（E5515C），CMU200,CMD55,CMD60,M58802A,8920A,8920B,8921A
 CharacteristicsThe
 CMD52 is a compact unit for testing GSM900 mobiles. The CMD55 is
 furthermore capable of testing GSM1800 (formerly named PCN orDCS1800)
 GSM1900 (formerly named PCSDCS1900) mobile phones. Both models
  are favourably pricedcombine small dimensions with high
 measurement accuracyspeed.The testers range of capabilities
 includes all signalling, generatormeasurement functions required
  for verifying the correct operation of the DUT (Device Under Test).
 Thanks to its fast go/nogo testsaccurate analysis using optional
  extensions, CMD52CMD55 are equally well suited for R&D, production
 and high-end serviceproduction.Based on the wide-range know-how
 of Rohde & Schwarz in digital radiocommunication testing, which not
 least was obtained in developing type-approval test systems such as
  the GSM900GSM1800 system simulators, both CMD models are top-
 grade testers for presentfuture measurement applications.Test
 capabilitiesTo test mobile phones, the CMD simulates a GSM900, 1800
 1900 base station. One of the two RF synthesizers available for
 this purpose delivers a continuous BCCH signal while the other one
 provides all 8 timeslots for TCH signals.The major test functions are
 :Mobile synchronizationLocation updateIncoming call setupOutgoing
 call setupMobile power level controlHandover (channel change, timeslot
  change)Peak power measurementHigh dynamic range burst analyzer
 (option CMD-B4CMD-B42)Spectrum due to Switching measurement
 (option CMD-B4CMD–B43)Spectrum due to Modulation measurement
 (option CMD-B4CMD–B43Timing Advance measurementSACCH measurement
  (eg RxLev, RxQual, power level)Echo testCall clearing by mobile
 phoneCall clearing by CMDDC current/voltage measurementsPhase
 frequency error measurement (option CMD-B4)Measurement of power
 ramping as a function of time (option CMD-B4)Bit-error rate (BER)
 Fast BER measurement (option CMD-B4)OperationOperation of the
 CMDis extremely user-friendlyrequires no detailed GSM/PCN knowledge.
 The high-contrast, backlit LCD provided with softkeys on both sides
 allows convenient callup of test routines under menu control. Various
  network-specific parameters are presetpermit direct testing
 without any operator control. In addition, it is of course possible
 to all parameters individually in the configuration menus.AutotestThe
 autotest function enables complete measurement routines to be started
  at a keystroke without any further intervention by the operator
  being required. The test results in tabular form are displayed on
 the screen.Remote controlThe CMD is remote-controlled via the RS-232
 IEEE/IEC-bus interface using SCPI-compatible commands. In the
 remote-control mode the CMD is designed for fast speed to yield high
  throughputs in production.Echo testThe echo test allows very rapid
 go/nogo analysis covering all essential parts of the mobile. Words
 spoken into the microphone of the mobile are sent to the CMD, stored
 in buffer memorysent back to the phone. In this way it is possible
  to check the whole signal path from the microphone via the RF transmitter
  section, RF receiver section, modulator, demodulator, signalling
 section, speech coder/decoder, analog audio components through to
 the loudspeaker.Testing handheldsIn addition to the normal RF input
 /output, the CMD has a high-sensitivity inputa high-level output
  which enable tests on moduleson handhelds with built-in antenna
 by using couplers like the CMD-Z10.Module testingFault localization
 in mobile telephones requires various measurement functions that can
  also be used without signalling so that defective units can be tested
 down to modular level. The basic model of CMD already provides some
 of these functions, eg signal generation withwithout modulation
 or power measurements, other functions being available as optional
 extensions.