Each Model SCIU Communication Interface Unit can link up to four YewSeries 80 instruments to the RS-485 (or RS-232C) bus of a central minicomputer or personal computer. Up to 16 SCIU Units can be connected to the RS-485 bus in a multidrop configuration to allow up to 64 YewSeries instruments to be supervised from the central computer. Simple command strings such as DG (Data Get) from the personal computer are used to access and set data.