I/O Terminal /
OVERVIEW
9
2.2 System
Overview
This section provides a system overview for the PROFIBUS Coupler.
2.2.1 Bus Terminal System
Up to 64 Bus Terminals each having 2 I/O Channels for each Signal Form
The Bus Terminal system is the universal interface between a fieldbus system and the
sensor / actuator level. A unit consists of a Bus Coupler as the head station, and up to 64
electronic series terminals, the last one being an end terminal. For each technical signal form,
terminals are available each having two I/O channels, and these can be mixed in any order. All
the terminal types have the same mechanical construction, so that difficulties of planning and
design are minimized. The height and depth match the dimensions of compact terminal boxes.
Decentralized Wiring of Each I/O Level
Fieldbus technology allows more compact forms of controller to be used. The I/O level does not
have to be brought to the controller. The sensors and actuators can be wired de-centrally, using
minimum cable lengths. The controller can be installed at any location within the plant.
Programmable Automation Controllers (PAC)
The use of a PAC as the controller means that the operating and observing element can be
implemented in the controller’s hardware. The controller can therefore be located at an operating
panel, in a control room, or at some similar place. The Bus Terminals form the decentralized
input/output level of the controller in the control cabinet and the subsidiary terminal boxes. The
power sector of the plant is also controlled over the bus system in addition to the sensor/actuator
level. The Bus Terminal replaces the conventional series terminal as the wiring level in the control
cabinet. The control cabinet can have smaller dimensions.
Bus Couplers for all Usual Bus Systems
The Bus Terminal system unites the advantages of a bus system with the possibilities of the
compact series terminal. Bus Terminals can be driven within all the usual bus systems, thus
reducing the controller parts count. The Bus Terminals then behave like conventional connections
for that bus system. All the performance features of the particular bus system are supported.
Assembly on Standardized C Mounting Rails
The easy, space-saving, assembly on a standardized C-rail, and the direct wiring of actuators and
sensors, without cross-connections between the terminals, standardizes the installation. The
consistent labeling scheme also contributes.
The small physical size and the great flexibility of the Bus Terminal system allow it to be used
wherever a series terminal is also used. Every type of connection, such as analog, digital, serial
or the direct connection of sensors can be implemented.
