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corresponds to –8.500 volts. These analog registers are available for
reading and writing by the user via the serial port and ASCII or
MODBUS commands. In addition, the new watch window functions
in Axiom+ software will allow monitoring of these register values
and also value assignment. Instructions in the sequential program
that require entering of a voltage value will also allow the
programmer to select an analog register. The PLC compare
operation now supports comparison of the analog input reading to a
register value. The sequential program also supports comparison of
the analog input to a hard-entered value or register value, and
general comparison of analog register values. Analog registers can
be assigned values by the sequential program as per other register
types. And there is a sequential instruction to store the present
analog input reading to an analog register for subsequent use.
ModBus Communication Setting
The Axiom Plus can be operated as a ModBus slave device. To do so,
the ModBus mode command flag (ICC 014) must be set. This can be
done in the PLC portion of the Axiom Plus, as described in Chapter
12. To ensure proper communication, the ModBus RTU protocol
communication framing and baud rate must be the same for both
Axiom Plus and its master. These can be configured in the Axiom
Plus indexer setup and configuration.
Figure 13.1 - ModBus Configuration and Setup Screen
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