Yokogawa EJX930A - Manual (Page 36)

<5. Configuration>
5-7
IM 01C25T02-01E
5.6.2 Trend Object
It is possible to set the parameter so that the
function block automatically transmits Trend. The
transmitter has seven Trend objects, six of which
are used for Trend in analog mode parameters and
one is used for Trend in discrete mode parameter.
A single Trend object specifies the trend of one
parameter.
Each Trend object has the parameters listed in
Table 5.8. The first four parameters are the items
to be set. Before writing to a Trend object, it is
necessary to release the WRITE_LOCK parameter.
Table 5.8 Parameters for Trend Objects
Sub-
index
Parameter Description
1 Block Index Sets the leading index
of the function block that
takes a trend.
2 Parameter Relative
Index
Sets the index of
parameters taking a trend
by a value relative to the
beginning of the function
block. In the DPharp
AI block, the following
three types of trends are
possible.
7: PV
8: OUT
19: FIELD_VAL
3 Sample Type Specifies how trends are
taken. Choose one of the
following 2 types:
1: Sampled upon
execution of a function
block.
2: The average value is
sampled.
4 Sample Interval Specifies sampling
intervals in units of 1/32
ms. Set the integer
multiple of the function
block execution cycle.
5 Last Update The last sampling time.
6 to
21
List of Status Status part of a sampled
parameter.
22 to
37
List of Samples Data part of a sampled
parameter.
Seven trend objects are factory-set as shown Table
5.9.
Table 5.9 Trend Object are Factory-Set
Index Parameters Factory Settings
32000 to
32005
TREND_FLT.1 to
TREND_FLT.6
Not used.
32006 TREND_DIS.1 Not used.
F0505.ai
SMIB
(System
Management
Information
Base)
NMIB
(Network
Management
Information
Base)
AI1 OUT AI2 OUT
FBOD
Alert
Trend
VCR
DLSAP
DLCEP
Fieldbus Cable
DPharp
0xF8 0xF3 0xF4 0xF7 0xF9 0x20 0x21 0x07
#1 #2 #3 #4
Resource
block
Transducer
block
Host 1 Host 2 Device 1 Device 2
Link
object
#1 #2 #3 #4 #5 #6 #7 #8 #9
Figure 5.5 Example of Default Configuration
5.6.3 View Object
This object forms a group of parameters in a
block. One advantage brought by forming groups
of parameters is the reduction of load for data
transactions. View Object has the parameters
listed in Table 5.11 to 5.14. Purpose of View Objects
is shown in Table 5.10.
Table 5.10 Purpose of Each View Object
Description
VIEW_1 Set of dynamic parameters required by
operator for plant operation. (PV, SV, OUT,
Mode etc.)
VIEW_2 Set of static parameters which need to be
shown to plant operator at once. (Range etc.)
VIEW_3 Set of all the dynamic parameters.
VIEW_4 Set of static parameters for configuration or
maintenance.