Cameron NUFLO MC-III, User Manual

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Section 4 MC-III™ Panel Mount Flow Analyzer
Communications Port
The Communications Port screen (Figure 4.18) allows users to change the settings that are required for
Modbus
®
communication.
Figure 4.18—Communications Port screen
Slave Address
The slave address allows the MC-III Panel Mount to communicate with other devices via Modbus
®
. It is a
number that ranges from 1 to 65535, excluding 252 to 255 and 64764. If a Modbus
®
request message contains
the matching slave address, the device will respond to the request. In network arrangements, the slave device
must have a unique address. For more information about Modbus
®
communications, refer to the protocol
manual section.
To change the slave address, select a number using the “plus” and “minus” buttons on the screen, or using the
page-up and page-down keys on your computer keyboard. If Modbus
®
communication is not used, leave the
slave address at the factory setting (1).
Baud Rate
The baud rate is the number of bits per second that are on the serial port. Baud rates supported by the MC-III
Panel Mount range from 300 to 115.2K. This setting must match the setting of the master device polling the
MC-III Panel Mount or the serial port. This only applies to the Modbus
®
communications; if Modbus
®
is not
used, set the baud rate to 9600.
To change the baud rate, slide the selector bar to the appropriate setting. The default setting is 9600 baud.
Note that the 9600 baud rate is available in both the low-power and high-power modes. When the instrument
is powered by batteries alone, the low-power mode is recommended.
Auto-Negotiate Option
When connected devices are capable of switching baud rates automatically or when devices are directly
connected to an MC-III Panel Mount, a user may configure the MC-III interface to automatically negotiate the