ABB S900 Manual

I/O System S900Communication Interface for PROFIBUS DP, CI9202. IntroductionSystem featuresI/O System S900 is a remote I/O system for use in hazardous areas. Itprovides bus-compatible local inputs and outputs (protection IP20) forconnection of digital and analog field instruments. Due to its degree ofexplosion protection it can be mounted in both hazardous areas (zone 1 andzone 2) and safe areas.The system consists of a mounting termination unit accommodating thepower supply units, the communication interfaces, and the I/O modules. Thepassive mounting termination unit ensures power distribution and datatransfer, and also provides the connection platform. The power supply unitsreliably power the entire system. One power supply unit is sufficient fornormal operation. A second (redundant) power supply unit can be added, toimprove the system availability. The communication interface controls alldata traffic between the I/O modules and the supervisory open control system(OCS) or the programmable logical controller (PLC). The communicationinterfaces CI920 can also be used in redundancy mode (line redundancy andCI920 redundancy)Figure 2-1 Remote I/O with a redundant power supply unit, a redundantcommunication interface, and 16 I/O modules (front view)The mounting termination unit is accommodated in a suitable field housing(junction box) to protect it from environmental exposure. Field mounting inhazardous areas requires approved field housings with increased safety3BDD010422R0101 9