Yokogawa FVX110 - Manual (Page 36)

<6. Configuration>
6-3
IM 01S01C01-01EN
6.3 Definition of Combining
Function Blocks
The input/output parameters for function blocks are
combined. As required, they can be combined with
the input of the control block. The setting is written
to the FVX110 link object. See “Block setting” in
Section 6.6 for the details. It is also possible to read
values from the host at proper intervals instead
of connecting the FVX110 block output to other
blocks.
The combined blocks need to be executed
synchronously with other blocks on the
communications schedule. In this case, change the
FVX110 schedule according to the following table.
The values in the table are factory-settings.
Table 6.3 Execution Schedule of the FVX110
Function Blocks
Index Parameters
Setting (Enclosed is
factory-setting)
269
(SM)
MACROCYCLE_
DURATION
Cycle
(MACROCYCLE)
period of control or
measurement. Unit
is 1/32 ms. (32000 =
1.0 s)
276
(SM)
FB_START_ENTRY.1 Excution block startup
time.
Elapsed time from the
start of MACROCYCLE
specified in 1/32 ms.
(0 = 0 s)
277
to
291
(SM)
FB_START_ENTRY.2
to
FB_START_ENTRY.16
Excution block startup
time.
Elapsed time from the
start of MACROCYCLE
specified in 1/32 ms.
(0 = 0 s)
A maximum of 30 ms is taken for execution of MAO
function block and IS function block. For scheduling
of communications for combination with the next
function block, the execution is so arranged as to
start after a lapse of longer than 30 ms. In no case
should function blocks of the FVX110 be executed
at the same time (execution time is overlapped).
Figure 6.3 shows an example of schedule based on
the loop shown in Figure 6.2.
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FIC100
FC100
FI100
EJX
#2
LI100
EJX
#1
LIC100
UI100
FVX
110
Figure 6.2 Example of Loop Connecting Function
Block of FVX110 and Two EJX with
Other Instruments
LI100
LIC100
FIC100 FC100
UI 100
FI100
Commu-
nication
Schedule
Macrocycle (Control Period)
IN
OUT
CAS_IN
BKCAL_OUT
BKCAL_IN
BKCAL_IN
BKCAL_OUT
IN
IN_1
IN_2
OUT
Unscheduled Communication
Scheduled Communication
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OUT
OUT
Figure 6.3 Function Block Schedule and
Communication Schedule
When the control period (macrocycle) is set to more
than 4 seconds, set the following intervals 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”