Fisher FIELDVUE DVC6200f Instruction Manual page 153

Instruction Manual
D103412X012
IN_1 through IN_8 and DISABLE_1 through DISABLE_8 are non‐volatile type parameters so if they are Linked they will
automatically have Bad status until connections are re‐established. If they are not Linked, they will be restored with the
previous value from NVM across device restarts.
Direct Selection of Inputs
The parameter OP_SELECT [22] can be used to select a particular input. If OP_SELECT [22] is non‐zero, the selection
algorithm is bypassed and the value of OP_SELECT [22] is interpreted as the input number to select. If the OP_SELECT
[22] value is greater than the number of inputs, then the highest input is selected. The status of OP_SELECT [22] must
be "Good," "Good_Cascade," or "Uncertain" with a STATUS_OPTS [10] of "Use Uncertain as Good" in order to be
evaluated. If the status of OP_SELECT [22] is Bad, then the OUT [7] status is Bad.
Identification of Selected Inputs
For a SELECT_TYPE [19] of Maximum, Minimum, Middle, First Good, and Hot Spare, SELECTED [21] indicates the
number of the selected input. When Middle is computed from more than one input, SELECTED [21] is set to 0.
For a SELECT_TYPE [19] of Average, SELECTED [21] indicates the number of inputs used in the average calculation.
When the block mode is Manual, SELECTED [21] is set to 0.
Alarm Detection
A block alarm will be generated whenever the BLOCK_ERR [6] has an error bit set. The types of block error for the PID
block are defined above.
Process alarm detection is based on OUT [7] value. You can configure the alarm limits of the following standard
alarms:
D High (HI_LIM [40])
D High high (HI_HI_LIM [38])
D Low (LO_LIM [42])
D Low low (LO_LO_LIM [44])
In order to avoid alarm chattering when the variable is oscillating around the alarm limit, an alarm hysteresis in percent
of the PV span can be set using the ALARM_HYS [36] parameter. The priority of each alarm is set in the following
parameters:
D HI_PRI [39]
D HI_HI_PRI [37]
D LO_PRI [41]
D LO_LO_PRI [43]
ACK_OPTION [35] is used to set automatic acknowledgement of alarms.
ALARM_SUM [34] indicates the current alert status, unacknowledged states, and disabled states of the alarms
associated with the function block.
Detailed Setup—ISEL Function Block
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