<4. Explanation of Basic Item>
4-3
IM 12A01A02-72E
3rd Edition : Oct. 01, 2015-00
4.4
Function Block Parameters
Function block parameters can be read from the host or can be set. For a list of the parameters of
blocks held by the FLXA21, refer to “3.6 PRIMARY/SECONDARY/TERTIARY/QUATERNARY_
VALUE Value Assignment”. The following is a list of important parameters with a guide how to set
them.
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Outline
This chapter describes brief explanation of the AI function block.
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Target Mode
The Target modes permitted for the AI function block are Automatic (Auto), Manual (Man), and
Out of Service (O/S). When the Target mode of PB (Physical Block) is Out of Service (O/S),
Actual is Out of Service (O/S) even if Automatic (Auto) or Manual (Man) is written to Target.
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Actual mode
Many parameters require a change of the mode of the function block to O/S (Out of Service)
when their data is changed. To change the mode of the function block, its Target Mode
(TARGET_MODE) needs to be changed. The Actual Mode (MODE_BLK) is comprised of the
three sub-parameters:
(1) Actual (Actual mode): Indicates the current operating condition.
(2) Permit (Permitted mode): Indicates the operating condition that the block is allowed to take.
(3) Normal (Normal mode): Indicates the operating condition that the block will usually take.
These mode parameter are very important as it gives the state of the block. In O/S (Out_Of_
Service) mode the block is out of operation. In this mode it is allowed to update parameters.
Manual mode gives the operator the possibility to manually update a selected number of
parameters (values, scaling e.g.) in order to test the system. In automatic mode the function
block is executed and block parameters are automatically updated.
Under normal operating circumstances, set the Auto mode for normal operation. Auto mode is
the factory default.
NOTE
The actual mode is changed by setting the target mode. When the physical block mode is set to
OOS all function blocks are set to OOS mode.
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CHANNEL
Channel is the parameter to select the signal which is calculated in SENSOR Transducer Block.
The values are assigned to channels.
For the FLXA21 three or four channels are available.
For the FLXA21, you can select from the PRIMARY, SECONDARY, TERTIARY, QUATENARY
values assigned to the Transducer Block.
For details on how to assign measurement items to parameters, refer to “3.6
SECONDARY/TERTIARY/QUATERNARY_VALUE Value Assignment”.
The following table shows the measurement items that you can select and their default values.