Yokogawa DO202 2-Wire Dissolved Oxygen Analyzer - Manual (Page 11)

IM 12A00A01-61E
3-6 Foundation Fieldbus
3-3 Configuration
This chapter contains information on how to adapt the function and performance of the EXA to suit specific
applications. Because two or more devices are connected to Fieldbus, settings including the requirements
of all devices need to be determined. Practically, the following steps must be taken.
(1) Network design
Determines the devices to be connected to Fieldbus and checks the capacity of the power supply.
(2) Network definition
Determines the tag and node addresses for all devices.
(3) definition of combining function blocks
Determines the method for combination between each function block.
(4) Setting tags and addresses
Sets the PD Tag and node addresses one by one for each device.
(5) Communication setting
Sets the link between communication parameters and function blocks.
(6) Block setting
Sets the parameters for function blocks.
The following section describes each step of the procedure in the order given. Using a dedicated configu-
ration tool allows the procedure to be signifi-cantly simplified. This section describes the procedure to be
assigned for a host which has relatively simple functions.
3-3-1 Network design
Select the devices to be connected to the Fieldbus network. The following instruments are necessary for
operation of Fieldbus.
• Power supply
Fieldbus requires a dedicated power supply. It is recommended that current capacity be well over the
total value of the maximum current consumed by all devices (including the host). Conventional DC
current cannot be used as is. A power conditioner is reguired.
• Terminator
Fieldbus requires two terminators. Refer to the supplier for details of terminators that are attached to the
host.
• Field devices
Connect the field devices necessary for instrumentation. EXA has passed the interoperability test
conducted by The Fieldbus Foundation. In order to properly start Fieldbus, it is recommended that the
devices used satisfy the requirements of the above test.
• Host
Used for accessing field devices. A minimum of one device with bus control function is needed.
• Cable
Used for connecting devices. Refer to “Fieldbus Technical Information” for details of instrumentation
cabling. Provide a cable sufficiently long to connect all devices. For field branch cabling, use terminal
boards or a connection box as required.