I/O Terminal /
OVERVIEW
10
Modularity
The modular assembly of the terminal strip with Bus Terminals of various functions limits the
number of unused channels to a maximum of one per function. The presence of two channels in
one terminal is the optimum compromise of unused channels and the cost of each channel. The
possibility of electrical isolation through potential feed terminals also helps to keep the number of
unused channels low.
Display of the Channel State
The integrated LEDs show the state of the channel at a location close to the sensors and
actuators.
Standard-Bus
The Standard-Bus is the data path within a terminal strip. The Standard--Bus is led through from
the Bus Coupler through all the terminals via six contacts on the terminals’ side walls. The end
terminal terminates the Standard-Bus. The user does not have to learn anything about the
function of the Standard-Bus or about the internal workings of the terminals and the Bus Coupler.
Many software tools that can be supplied make project planning, configuration and operation
easy.
Potential Feed Terminals for Isolated Groups
The operating voltage is passed on to following terminals via three power contacts. You can
divide the terminal strip into arbitrary isolated groups by means of potential feed terminals. The
potential feed terminals play no part in the control of the terminals, and can be inserted at any
locations within the terminal strip.
Up to 64 terminals can be used within one terminal strip. This count does include potential feed
terminals, but not the end terminal.
Bus Couplers for Various Fieldbus Systems
Various Bus Couplers can be used to couple the electronic terminal strip quickly and easily to
different fieldbus systems. It is also possible to convert to another fieldbus system at a later time.
The bus coupler performs all the monitoring and control tasks that are necessary for operation of
the connected Bus Terminals. The operation and configuration of the Bus Terminals is carried out
exclusively by the Bus Coupler. Nevertheless, the parameters that have been set are stored in
each Bus Terminal, and are retained in the event of voltage drop-out. Fieldbus, Standard--Bus
and I/O level are electrically isolated.
If the exchange of data over the fieldbus is prone to errors or fails for a period of time, register
contents (such as counter states) are retained, digital outputs are cleared, and analog outputs
take a value that can be configured for each output when commissioning. The default setting for
analog outputs is 0 V or 0 mA. Digital outputs return in the inactive state. The timeout periods for
the Bus Couplers correspond to the usual settings for the fieldbus system. When converting to a
different bus system it is necessary to bear in mind the need to change the timeout periods if the
bus cycle time is longer.
The Interfaces
A Bus Coupler has six different methods of connection. These interfaces are designed as plug
connectors and as spring-loaded terminals.
