Serial data bus with central processor and remote terminals

摘要

The data installation (10) comprises a bus (24) to which several remote terminal units (30,32) and a central processor (18) are connected. The latter is connected to a central command unit (12), e.g. a process computer. The remote units (30,32) communicate (14,16) with the equipment which they control. A power supply (36) can be included in the bus system.To reduce the effects of interference the bus is made with a known characteristic impedance. Each end of the bus is terminated in a low pass filter (16,28) of matching impedance