SERCON410B Datasheet, PDF (9/34 Pages) STMicroelectronics – SERCOS INTERFACE CONTROLLER

SERCON410B
1 GENERAL DESCRIPTION
The SERCOS interface controller SERCON410B
is an integrated circuit for SERCOS interface com-
munication systems. The SERCOS interface is a
digital interface for communication between sys-
tems which have to exchange information cycli-
cally at short, fixed intervals (65 µs to 65 ms). It is
appropriate for the synchronous operation of dis-
tributed control or test equipment (e.g. connection
between drives and numeric control).
A SERCOS interface communication system con-
sists of one master and several slaves (Fig. 3).
These units are connected by a fiber optical ring.
This ring starts and ends at the master. The slaves
regenerate and repeat their received data or send
their own telegrams. By this method the telegrams
sent by the master are received by all slaves while
the master receives data telegrams from the
slaves. The optical fiber assures a reliable high-
speed data transmission with excellent noise im-
munity.
The SERCOS interface controller contains all the
hardware-related functions of the SERCOS inter-
face and considerably reduces the hardware
costs and the computing time requirements of the
microprocessor. It is the direct link between the
electro-optical receiver and transmitter and the mi-
croprocessor that executes the control algorithms.
The SERCON410B can be used both for SERCOS
interface masters and slaves.
The circuit contains the following functions (Fig. 1):
- ^{Interface to the microprocessor with a data}
bus width of 8 or 16 bits and with control lines
according to Intel or Motorola standards.
- ^{A serial interface for making a direct connec-}
tion with the optical receiver and transmitter of
the fiber optic ring or with drivers to an electric
ring or bus. Data and clock regeneration, the
repeater for ring topologies and the serial
transmitter and receiver are integrated. The
signals are monitored and test signals gener-
ated. The serial interface operates up to
4Mbaud without external circuitry and up to 10
Mbaud with external clock regeneration.
- ^{A dual port RAM (1024 * 16 bit) for control and}
communication data. The organization of the
memory is flexible.
- ^{Telegram processing for automatic transmis-}
sion and monitoring of synchronous and data
telegrams. Only transmission data which is in-
tended for the particular interface user is proc-
essed. The transmitted data is either stored in
the internal RAM (single or double buffer) or
transferred via direct memory access (DMA).
The transmission of service channel informa-
tion over several communication cycles is exe-
cuted automatically.
In addition to the SERCOS interface the SER-
CON410B can also be used for other real-time
communications tasks. As an alternative to the fi-
beroptical ring also bus topologies with RS-485
signals are supported (Fig. 4). The SERCON410B
is therefore suitable for a wide range of applica-
tions.
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