Yokogawa DO202 2-Wire Dissolved Oxygen Analyzer - Manual (Page 10)

IM 12A00A01-61E
Foundation Fieldbus 3-5
3-2-4 Integration of dd
If the host supports DD (Device Description), the DD of the EXA needs to be installed. Check if host has the
following directory under its default DD directory.
594543\DEV_TYPE
(594543 is the manufacturer number of Yokogawa Electric Corporation, and DEV_TYPE is the EXA device
number, respectively.)
If this directory is not found, DD of EXA has not been included. Create the above directory and copy the DD
file (0m0n.ffo,0m0n.sym) (m, n is a numeral) (to be supplied separately) into the directory.
Once the DD is installed in the directory, the name and attribute of all parameters of the EXA are displayed.
Off-line configuration is possible by using Capability file (CFF).
3-2-5 reading the Parameters
To read EXA parameters, select the AI1 block of the EXA from the host screen and read the OUT param-
eter. The current process value is displayed. Check that MODE_BLOCK of the function block and resource
block is set to AUTO.
3-2-6 Continuous record of values
If the host has a function of continuously recording the indications, use this function to list the indications
(values). Depending on the host being used, it may be necessary to set the schedule of Publish (the func-
tion that transmits the indication on a periodic basis).
3-2-7 Generation of Alarm
If the host is allowed to receive alarms, generation
of an alarm can be attempted from EXA. In this case, set the reception of alarms on the host side. EXA’s
VCR-7 is factory-set for this purpose. For practical purposes, all alarms are placed in a disabled status; for
this reason, it is recommended that you first use one of these alarms on a trial basis. Set the value of link
object-3 (index 30002) as “0, 299, 0, 6, 0”. Refer to section 3-3-6-1 Link Object for details.
Since the LO_PRI parameter (index 4029) of the AI1 block is set to “0”, try setting this value to “3”. Select
the Write function from the host in operation, specify an index or variable name, and write “3” to it.
The LO_LIM parameter (index 4030) of the AI1 block
determines the limit at which the lower bound alarm for the process value is given. In usual cases, a very
small value is set to this limit. Set a value higher than the current process value, a lower bound alarm is
raised. Check that the alarm can be received at the host. When the alarm is confirmed, transmission of the
alarm is suspended.
The above-mentioned items are a description of the simple procedure to be carried out until EXA is con-
nected to Fieldbus. In order to take full advantage of the performance and functionality of the device, it is
recommended that it be read together with Chapter 5 of relevant User’s Manual, which describes how to
use the EXA.