Thermo Fisher Scientific Micro-Tech 9101/9201 Reference Manual, Rev J C-65
The PROFIBUS is one of the main standardized communication systems.
All its characteristics, rules and technical information are defined in the
PROFIBUS DIN normative.
There are three main variations of PROFIBUS corresponding to the
intended application: PROFIBUS-FMS, PROFIBUS-DP and PROFIBUS-
PA.
The Micro-Tech variation is PROFIBUS-DP.
Profibus-DP is the performance-optimized version specifically dedicated to
time-critical communication between automation systems and distributed
peripherals. It is typically used to transfer I/O images between a main PLC
and remote devices (sensors, actuators, transmitters, etc.). In this case, it
will be used to transfer (read and write) blocks of data.
Profibus is a typical master/slave communication where the main PLC is
the master or scanner, and the Micro-Tech device is a slave. The
connection is EIA RS 485 through a 2-wire twinax cable.
The interface between the master and slaves is structured in
parameterization, configuration, and data transfer phase. In the
parameterization and configuration phases, each slave compares its real
configuration with the configuration data received from the master. When
verifying the configuration, device type, format and length of information
have to be identical. This guarantees a protection against a configuration
fault. Maximum number of data that is possible to transfer in this phase at
one time is limited to 246 bytes (123 words).
Besides the configuration, check to avoid erroneous configurations, the
slave uses the watch dog control to detect failures on the bus. If a slave
recognizes no successful data transfer with the master within the watch dog
control interval, it generates an alarm condition.
The PROFIBUS-DP interface board (Optional) is a plug-in board that can
be installed in one of the motherboard expansion slots J10-J13 and that
handles the interface between the Micro-Tech (slave) and the master.
No hardware configuration jumpers or switches are present on the
PROFIBUS-DP board.
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