KUNBUS-COM EtherCAT
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SSC Master Operating Mode
In this operating mode, output data is read from the SSC output
register area via the serial synchronous interface and input data is
written to the SSC input register area. This takes place via a
hardware shift register chain.
Illustration 11:
Hardware shift register chain, example with 4 inputs and outputs
The advantage of such an interface is the possibility of forwarding
input and output signals to the fieldbus without the need of
microprocessor controlled application circuitry. Switches, contacts,
relay coils or solenoid valves, for example, can therefore be
connected directly via EtherCAT without using a microprocessor.
The COMS-Modul with its clock (Pin a4) clocks the output data into
the input register of the chain via the MOSI line (Pin a5), where it is
shifted bit by bit until the end. At the same time, the input data is
shifted bit by bit via the MISO line into the COMS-Modul with the
same clock pulse. Prior to each such shift procedure, the module
sets the LOAD line to high (Pin b6). In this way, the parallel outputs
Components
