What is a Multiplexer?
A multiplexer, sometimes referred to as a “multiplexor” or simply “mux”, is a device that selects between a number of input signals. In its simplest form, a multiplexer will have two signal inputs, one control input, and one output. An everyday example of an analog multiplexer is the source selection control on a home stereo unit. Multiplexers are used in building digital semiconductors such as CPUs and graphics controllers. In these applications, the number of inputs is generally a multiple of 2 (2, 4, 8, 16, etc.), the number of outputs is either 1 or relatively small multiple of 2, and the number of control signals is related to the combined number of inputs and outputs. For example, a 2-input, 1-output mux requires only 1 control signal to select the input, while a 16-input, 4-output mux requires 4 control signals to select the input and 2 to select the output. Multiplexers are also used in communications; the telephone network is an example of a very large virtual mux built from m
A multiplexer or a mux is a device that selects one of many inputs and routes it to a single output. Multiplexer (mux) switch modules are perfect for increasing the channel count of a single instrument. For example, you can use a multiplexer (mux) to connect a digital multimeter or oscilloscope to many measurement points on a UUT, or connect an arbitrary waveform generator to several points needing excitation. With multiplexer switches, you can reduce your instrumentation costs while maintaining maximum system flexibility. A multiplexer is not as appropriate for systems that require many test points routed to multiple instruments. In that case, your ideal choice is a matrix. Refer to the National Instruments PXI Matrix Products page for more information on NI’s matrix offering.
A Simplex Multiplexer lets the user to view a single Camera “live” screen, while other full screen displays are being recorded. User can review the video tapes, camera by camera. In order to review the video tapes, the playback must be done through the Multiplexer. In order to review the video tapes on a Simplex Multiplexer, the recording mode must be quitted. You can not play and record simultaneously on a single recorder. A Duplex Multiplexer let the user to view single camera “live” screen, while other full screen displays are being recorded. On a Duplex Multiplexer, user can review the video tapes and record simultaneously, one recorder does the playback and the second recorder does the recording.
It quite often happens, in the design of large-scale digital systems, that a single line is required to carry two or more different digital signals. Of course, only one signal at a time can be placed on the one line. What is required is a device that will allow us to select, at different instants, the signal we wish to place on this common line. Such a circuit is referred to as a Multiplexer. A multiplexer performs the function of selecting the input on any one of ‘n’ input lines and feeding this input to one output line. Multiplexers are used as one method of reducing the number of integrated circuit packages required by a particular circuit design. This in turn reduces the cost of the system. Assume that we have four lines, C0, C1, C2 and C3, which are to be multiplexed on a single line, Output (f). The four input lines are also known as the Data Inputs. Since there are four inputs, we will need two additional inputs to the multiplexer, known as the Select Inputs, to select which of
Put simply, a multiplexer allows several camera signals to be recorded onto one videotape. To do this it synchronizes the camera signals (lines them up in time) and marks each one with a code, allowing every camera to be replayed independently from tape, regardless of how many cameras are recorded on that tape. In addition, each image is stamped with a time and date caption. Many multiplexers also provide the ability to view several cameras simultaneously on one or more monitors. This is useful when there is a large number of cameras on a system. Simplex vs. Duplex In order to select the right multiplexer, it is important to understand the difference between simplex and duplex operation. These terms refer to how the multiplexer functions during recording and playback. A simplex multiplexer permits recording or playback. Therefore the system is not recording when tapes are being reviewed. Duplex multiplexers can multitask to provide simultaneous recording and playback. Duplex operation
