Many function blocks have parameters that contain bit-encoded information to specify options that are available to you. There are several types of option bitstrings:
Control Options – allow you to select control strategy options.
I/O Options – allow you to select how the I/O signals are processed.
Status Options – allow you to select options for status handling and processing.
Integration Options – allow you to specify integration and reset behavior.
Device Options – allow you to select device controller logic options.
Algorithm Options – allow you to specify abort or no-abort on read errors.
Input Options – allow you to set the options for using IN and IN_LO when Uncertain. They also allow you to set the options for using IN_1, IN_2 and IN_3 when any are either Bad or Uncertain.
FSRI Add-On Options – allow you to select additional control and I/O options for the DeltaV blocks.
Interlock Option – Allows you to select the block's behavior when the status of INTERLOCK_D, PERMISSIVE_D, or SHUTDOWN_D is not Good.
Tracking Option – Allows you to select the tracking behavior when the status of the tracked variable is not Good.
Supported options vary with each function block. The following sections contain tables that list the blocks that implement each option. In addition, the Books Online information on each function block lists the supported options for that block.
The control options parameter (CONTROL_OPTS) allows you to select control strategy options. You can set control options in Manual or Out of Service mode only. The following are the control options in the DeltaV system:
Use BKCAL_OUT With IN_1 – Normally, BKCAL_OUT is associated with initialization of an upstream block that is providing CAS_IN. If this option is set, then BKCAL_OUT is associated with the upstream block providing IN_1. This option is used with the Ratio and Bias/Gain block to determine the value and status that must be provided in BKCAL_OUT for proper initialization and handshaking.
No OUT Limits in Manual – Do not apply OUT_HI_LIM or OUT_LO_LIM when target and actual modes are Man.
Obey SP Limits if Cas or RCas – Normally a cascaded setpoint is not restricted to the downstream block setpoint limits except when entered by a human interface device. However, if this option is selected, the cascaded setpoint is restricted to the setpoint absolute limits in the Cas and RCas modes. If a downstream block SP limit is reached and the cascade loop is not configured for Dynamic Reset Limiting, integral action is suspended on the upstream block when the error is driving the upstream block into the limit.
Act on IR – Used to back calculate for bumpless transfer.
In the Bias/Gain function block as well as the Ratio function block, if this option is true, when the block is in a non-automatic mode or transitions to an automatic mode, the SP will be back calculated for purposes of bumpless transfer. The back calculated SP will be limited to the range defined by the SP limits. Any difference between the value required for bumpless transfer will be added to OUT and then ramped out over BAL_TIME.
In the PID block, if this option is true and the STRUCTURE parameter is set to PD, then, when the block transitions to an automatic mode from a non-automatic mode the BIAS is back calculated for bumpless transfer.
Use PV for BKCAL_OUT – Normally, BKCAL_OUT contains the value of the working setpoint (SP_WRK). When necessary, use the process variable (PV) instead by turning on the Use PV for BKCAL_OUT control option. Note that even when this control option is turned on, it is enforced only when the block is in Cas mode. When the block is in a non-Cas mode, SP_WRK is used for BKCAL_OUT.
Track in Manual – Enables external tracking for target mode of MAN when Track Enable option has been selected. If Track In Manual is not selected then external tracking is prevented with a target mode of MAN, and, switching to a target mode of MAN will stop external tracking if external tracking had previously been initiated.
Track Enable – Enables external tracking function. If Track Enable option is selected, then, when TRK_IN_D is true, and, the target mode is not MAN or the Track In Manual option is selected, the block is placed in LO, the block output is set to the value of TRK_VAL.
Direct Acting – Defines the relationship between a change in PV and the corresponding change in output. When Direct Acting is enabled (True), an increase in PV results in an increase in the output.
SP Track Retained Target – Permits the setpoint to track the RCas or Cas parameter based on the retained target mode when the actual mode of the block is IMan, LO, Man, or ROut. SP Track Retained Target has precedence over the other SP-PV track options in the selection of the value to track when the actual mode is IMan, LO, Man, or ROut.
SP-PV Track in LO or IMan – Permits the SP to track the PV when the actual mode of the block is LO or IMan. SP-PV Track in Man takes precedence over SP-PV Track in LO or IMan. SP-PV Track in Man must be enabled in order for SP-PV Track in LO or IMan to track when Target mode is MAN.
SP-PV Track in ROut – Permits the setpoint to track the process variable when the actual mode of the block is ROut.
SP-PV Track in Man – Permits the SP to track the PV when the target mode of the block is Man.
Bypass Enable – This parameter, if true, allows BYPASS to be set. Some control algorithm applications cannot provide closed loop control if bypassed.
The I/O options parameter (IO_OPTS) allows you to select how the I/O signals are processed. You can set I/O options in Manual or Out of Service mode only. The following are the I/O options in the DeltaV system:
Low Cutoff – Changes any calculated output below this value to a zero output value. This is useful for zero-based measurement devices such as flowmeters.
Use PV for BKCAL_OUT – Changes the BKCAL_OUT value to the PV value. When the Use PV for BKCAL_OUT option is not enabled (False), the BKCAL_OUT value is the working setpoint value.
Target to Man if Fault State activated – Set the target mode to Man, thus losing the original target, if Fault State is activated. This latches an output block into the manual mode.
Use Fault State value on restart – Use the value of FSTATE_VAL(_D) if the device is restarted, otherwise use the non-volatile value. This does not act like Fault State, it only uses the value of FSTATE.
Fault State to value – The output action to take when fault occurs. (0: freeze, 1: go to preset value)
Increase to Close – Indicates whether or not the output value is inverted before it is communicated to the I/O channel.
SP-PV Track in LO or IMan – Permits the SP to track the PV when the actual mode of the block is LO or IMan. SP-PV Track in Man takes precedence over SP-PV Track in LO or IMan. SP-PV Track in Man must be enabled in order for SP-PV Track in LO or IMan to track when Target mode is MAN.
SP-PV Track in Man – Permits the SP to track the PV when the target mode of the block is Man.
Invert – Indicates whether the discrete input should be logically inverted before it is stored in the process variable. A discrete value of zero (0) will be considered to be a logical zero (0) and a non-zero discrete value will be considered to be a logical one (1). For example, if invert is selected, the logical NOT of a non-zero field value would result in a zero (0) discrete output, and the logical NOT of a zero field value would result in a discrete output value of one (1).
Note IMan is not possible in an I/O block.
The status options parameter (STATUS_OPTS) allows you to select options for status handling and processing. You can set status options in Manual or Out of Service mode only. The following are the status options in the DeltaV system:
Uncertain if Man mode – Set the output status of an input or calculation block to Uncertain if the actual mode of the block is Man.
BAD if Limited – Sets the output status to Bad if the sensor is at or beyond a high or low limit.
Uncertain if Limited – Set the output status of an input or calculation block to Uncertain if the measured or calculated value is limited.
Target to Manual if Bad IN – Sets the target mode to Man if the status of the IN parameter is BAD.
Propagate Fault Backward – If the status from the actuator is Bad - Device Failure or Fault State Active or Local Override is active, propagate this as Bad, Device Failure or Good Cascade, Fault State Active or Local Override to BKCAL_OUT respectively without generating an alarm. The use of these substatuses in BKCAL_OUT is determined by this option. Through this option, the user can determine whether alarming (sending of an alert) will be done by the block or propagated upstream for alarming.
Propagate Fault Forward – If the status from the sensor is Bad - Device Failure or Bad - Sensor Failure, propagate it to OUT without generating an alarm. The use of these substatuses in OUT is determined by this option. Through this option, the user can determine whether alarming (sending of an alert) will be done by the block or propagated downstream for alarming.
Use Uncertain as Good – If the status of the IN parameter is Uncertain, treat it as GOOD.
IFS if Bad CAS_IN – Set Initiate Fault State status in the OUT parameter if the status of the CAS_IN parameter is BAD.
IFS if Bad IN – Set Initiate Fault State status in the OUT parameter if the status of the IN parameter is BAD.
The integration options parameter (INTEG_OPTS) allows you to specify integration and reset behavior. You can set integration options in any mode. The following integration options are supported in the Integrator function block:
Carry – Determines what to do with the integration value after a reset condition is reached. When the Carry option is not enabled (False), the integrated value starts over (at zero or SP) when it is reset. When the Carry option is enabled (True), the excess values are carried over past the trip point into the next integration cycle as the initial value of the integrator.
Flow Reverse – Determines the net flow direction. When Flow Reverse is selected (True), negative increments are included in the integration.
Flow Forward – Determines the net flow direction. When Flow Forward is selected (True), positive increments are included in the integration.
When both Flow Forward and Flow Reverse are selected, positive and negative increments are included in the integration.
The device options parameter (DEVICE_OPTS) allows you to select device controller logic options. You can set device options in any mode. The following device options are supported in the Device Control function block:
Interlock – When the Interlock option is enabled (True) and the INTERLOCK_D input is False, OUT_D is set to the Passive state and is held there until INTERLOCK_D is set to True.
SP Track – When the SP Track option is enabled (True), SP_D tracks OUT_D when the actual mode is Local Override (LO).
Warning Disabling this option can potentially start the equipment when unattended if the SP is left Active following a failed start due to an interlock.
Permissive – Allows OUT_D to transition from a Passive state to an Active state or from one Active state to another when SP_D requests. When the Permissive is enabled (True) and the PERMISSIVE_D input is set True, OUT_D is allowed to transition from the Passive state to an Active state or from one Active state to the other when SP_D requests.
Reset Required – When the Reset Required option is enabled (True) and OUT_D is forced to Passive because of an interlock, shutdown, or run confirmation failure, OUT_D remains at Passive until RESET_D is set to True.
Trip – When the Trip option is enabled (True) and an Active Confirm is lost for a time greater than TRIP_TIME, OUT_D is set to Passive. The SP_D value must return to Passive to clear the tripped condition. When the Reset Required option is enabled (True), RESET_D must also be set to True to clear the tripped condition.
Passive when Confirmed – When the Passive when Confirmed option is enabled (True) and the field device is confirmed to the desired Active state, OUT_D is changed to the Passive state.
Passive on Active Timeout – When the Passive on Active Tim-out option is enabled (True) and an Active state is not confirmed within the confirm time following a command to an Active state, OUT_D is changed to the Passive state.
The algorithm options parameter (ALGO_OPTS) allows you to specify abort or no-abort on read errors. The ALGO_OPTS parameter is supported in the Action, Calculation/Logic, and Condition function blocks.
AbortOnReadErrors - When selected, the expression algorithm aborts
after encountering a read error on any parameter. A read error occurs, for
example when a parameter in another controller cannot be read because the
controllers are not communicating.
When the expression aborts, the following occurs:
Condition block – PRE_OUT_D retains its value from the previous scan
Action block – None of the assignment statements are executed
Calc/Logic block – None of the assignment statements are executed
The input options (INPUT_OPTS) allow you to set the options for using IN and IN_LO when Uncertain. They also allow you to set the options for using IN_1, IN_2 and IN_3 when any are either Bad or Uncertain. When a particular option is not selected and the status is Bad or Uncertain, the last usable value is used. A value is usable if the status is Good or if the status is not Good but the input option for that status (Bad or Uncertain) is selected to use it. To change the input options while using the on-line view, first change the mode to OOS. The following input options are supported in the Arithmetic function block:
IN_3 Use Bad – If selected, the IN_3 Use Bad option uses the value of IN_3, even if the status equals Bad.
IN_3 Use Uncertain – If selected, the IN_3 Use Uncertain option uses the value of IN_3, even if the status equals Uncertain.
IN_2 Use Bad – If selected, the IN_2 Use Bad option uses the value of IN_2, even if the status equals Bad.
IN_2 Use Uncertain – If selected, the IN_2 Use Uncertain option uses the value of IN_2, even if the status equals Uncertain.
IN_1 Use Bad – If selected, the IN_1 Use Bad option uses the value of IN_1, even if the status equals Bad.
IN_1 Use Uncertain – If selected, the IN_1 Use Uncertain option uses the value of IN_1, even if the status equals Uncertain.
IN_LO Use Uncertain – If selected, the IN_LO Use Uncertain option uses the value of IN_LO, even if the status equals Uncertain.
IN Use Uncertain – If selected, the IN Use Uncertain option uses the value of IN, even if the status equals Uncertain.
There are two classes of FRSI add-on options, FRSIRB and FRSIPID. The FRSIRB options are add-on I/O options for the DeltaV Bias/Gain and Ratio blocks. The FRSIPID options are add-on control options for the DeltaV PID block.
ADD-ON I/O OPTIONS (FRSIRB_OPTS)
Treat IN1 as Wild
Causes cascade input on IN_1 to be interpreted as cascade closed, regardless of substatus on the function block.
ADD-ON CONTROL OPTIONS (FRSIPID_OPTS)
Dynamic Reset Limit
Is the reset term based upon the control parameter (BKCAL_OUT) of the downstream block. Prevents windup caused by limiting of the downstream block or from dynamic performance because of tuning. The downstream block must have Use PV for BKCAL_OUT set as an I/O option for Dynamic Reset Limit option to be used in the upstream block.
Use Nonlinear GainModification
When False, the gain modifier is 1.0. Otherwise, it is calculated.
Use Delayed OUT on Bad PV
When the status of PV becomes Bad and the mode transitions to Man because of the Bad PV status, the value of OUT is 5 scans previous.