Yokogawa digitalYEWFLO (DY-FF) - Manual (Page 20)

<5. CONFIGURATION>
5-3
IM 01F06F00-01EN
Table 5.3 Function Block Execution Schedule of
the digitalYEWFLO
Index Parameters
Setting (Factory Setting
in Parentheses)
269 (SM) MACROCYCLE_
DURATION
Repetition period of control
or measurement, i.e.,
macrocycle; to be set as a
multiple of 1/32 ms (32000
= 1 second)
276 (SM) FB_START_ENTRY.1 Start time of the AI1
block represented as the
elapsed time from the start
of each macrocycle; to be
set as a multiple of 1/32 ms
(0 = 0 ms)
277 (SM) FB_START_ENTRY.2 Start time of the PID block
(optional) represented as
the elapsed time from the
start of each macrocycle;
to be set as a multiple of
1/32 ms (9600 = 300 ms)
278 (SM)
to
289 (SM)
FB_START_ENTRY.3 to
FB_START_ENTRY.14 Not set.
A maximum of 29 ms is taken for execution of each
AI block. Arrange the communication schedule
for an AI block’s data that is to be transferred to its
downstream block in such a way that it starts after a
lapse of longer than 30 ms.
Figure 5.3 shows typical function block and
communication schedules for the loop shown in
Figure 5.2.
F0502.ai
FIC100
FIC200
FC100
FI200
digitalYEWFLO
#2
FI100
digitalYEWFLO
#1
Figure 5.2 Example of Loop Connecting Function
Blocks of Two digitalYEWFLOs with
Other Devices
FI103 FI100
FC100 FIC100
FC200 FIC200 FC100
FI200 FI200
Function
Block
Schedule
Commu-
nication
Schedule
OUT
IN
OUT
CAS_IN
BKCAL_OUT
BKCAL_IN
BKCAL_IN
BKCAL_OUT
IN
Unscheduled
Communication
Scheduled
Communication
F0503.ai
Macrocycle (Control Period)
Figure 5.3 Function Block Schedule and
Communication Schedule
When the control period (macrocycle) is set to more
than 4 seconds, set the following interval to be more
than 1% of the control period.
- Interval between “end of block execution”
and “start of sending CD from LAS”
- Interval between “end of block execution”
and “start of the next block execution”
5.4 Setting of Tags and Addresses
This section describes the steps in the procedure
to set the PD tags and node address in the
digitalYEWFLO. There are three states of Fieldbus
devices as shown in Figure 5.4, and if the state
is other than the lowest SM_OPERATIONAL
state, no function block is executed. Whenever
you have changed the PD tag or address of
a digitalYEWFLO, transfer its state to SM_
OPERATIONAL.
UNINITIALIZED
(No tag nor address is set)
Tag clear Tag setting
INITIALIZED
(Only tag is set)
SM_OPERATIONAL
(Tag and address are retained, and
the function block can be executed.)
Address clear
F0504.ai
Address setting
Figure 5.4 Status Transition by Setting PD Tag and
Node Address