This manual covers the technical aspects of the PCD1 and PCD2 components.
The following terms are used frequently:
● CPU Central processing unit: the heart of the PCD
● RIOs Remote I/Os: inputs and outputs connected to the CPU via a field bus such as Profibus
● LIOs Local I/Os: these are connected to the CPU via the I/O bus or a RIO (i.e., with the shortest possible cables)
● Modules Input/output elements, mounted in a housing, matched to the PCD1/2 system
● Module holders CPUs, RIOs or LIOs, to which modules may be attached
The aim of the Overview section is to present the essentials of planning and installing control systems with PCD1/2 components.
It covers the following topics:
● Planning an application
● Cabling Details of hardware, software, configuration, maintenance and troubleshooting are described in separate sections
Planning an application with PCD1/2/3 components.
The following aspects should be considered when planning PCD1/2 applications:
● The internal load current taken by the I/O modules from the +5 V and V+ supply must not exceed the maximum supply current specified for the CPUs
● The CPU type determines the maximum number of modules
● The total length of the I/O bus is limited by technical factors; the shorter, the better
