Fieldbus Parameters (in alphabetical order)

Overview

This document lists the most common Fieldbus parameters in alphabetical order.

Contents

Fieldbus Parameters A-B

ACK_OPTION
Allows alarms to be automatically acknowledged by the block with no outside intervention. This is useful if you are not interested in acknowledging certain alarms from a block.

ALARM_HYS
The amount a value must move off an alarm limit, in percent of scale, for the alarm to be considered clear. This helps prevent alarms from constantly “toggling” on and off when the process value is near the configured alarm limit.

ALARM_SUM
A summary of the status of alarms in the block. Allows alarms to be disabled.

ALERT_KEY
A user-assigned identification number reported in alarm messages from the block that allows HMI applications to sort and filter alarms and events. This parameter is set for each function block to indicate which physical unit the function block is associated with.

BAL_TIME
Time, in seconds, for the bias or ratio to change from the internal working value to the operator set value. Also, the time constant used by the integral term of the PID to obtain balance when the output is limited and the block is in Auto, Cas, or RCas mode.

BIAS
The bias value, in engineering units, used to calculate the function block output.

BKCAL_HYS
The amount a block’s output value must move off a limit, in percent of scale, for the limit status to be turned off.

BKCAL_IN
Will be linked to a downstream block’s BKCAL_OUT or SELECT_OUT parameter. This is used to initialize a control loop through cascade initialization. Cascade initialization allows smooth transfer for a control block from Manual to Auto mode. To bypass cascade initialization, this parameter can be left unwired and manually set to a status of Good, non-cascade.

BKCAL_OUT
A back-calculation value published to the BKCAL_IN of an upstream block in a control loop. The BKCAL_OUT parameter has the value of the block’s current output. Before a cascade loop is initialized, the upstream block can use this value to smoothly transfer to loop control.

BKCAL_OUT_D
An output value published to an upstream discrete block. The upstream block can use this value to smoothly transfer to loop control.

BLOCK_ALM
An alarm parameter used to report error conditions detected within the block, such as block Out of Service.

BLOCK_ERR
A list of error conditions for hardware and software components associated with the block. The following table lists all active error codes.


Error Codes
Error Code
Code
Description
Other 0x0001 Undefined block error condition.
Block Configuration Error 0x0002 The block has detected an error in its configuration. This usually indicates a static parameter has been left uninitialized.
Link Configuration Error 0x0004 The logical connection between this block and another block is misconfigured.
Simulate Active 0x0008 For I/O function blocks, this indicates that simulation is enabled. For the resource block, this indicates that the simulate jumper has been set, allowing simulation to be enabled in other blocks.
Local Override 0x0010 The block has locally overridden the output value. This can be the result of an interlock or faultstate.
Device Faultstate Set 0x0020 The block’s faultstate behavior is active.
Device Needs Maintenance Soon 0x0040 The device is reporting performance degradation that will soon require maintenance.
Input Failure/BAD PV Status 0x0080 Either the input transducer channel has reported a failure, or the input parameter from an upstream block has reported a failure. For an AI block, this could be caused by an open circuit being detected on the FP-AI-100 input module.
Output Failure 0x0100 The output transducer channel has reported a failure. For an AO block, this could indicate that the FP-AO-200 cannot drive the current request, perhaps due to an open circuit.
Memory Failure 0x0200 The storage for nonvolatile and static parameters was corrupted.
Lost Static Data 0x0400 The device was unable to restore the values of static parameters after a restart.
Lost NV Data 0x0800 The device was unable to restore the values of nonvolatile parameters after a restart.
Readback Check Failed 0x1000 The value read back from the output channel does not match the value the output channel was set to.
Device Needs Maintenance Now 0x2000 The device needs to be maintained now.
Power-Up 0x4000 The device has just powered up.
Out of Service 0x8000 The block is currently out of service.


BYPASS
Allows the normal control algorithm to be bypassed if the CONTROL_OPT parameter’s Bypass Enable option is selected. If control is bypassed, the PID uses its setpoint value in percent of scale as its output value and does not attempt to do any PID control.

Fieldbus Parameters C-F


CAS_IN
A remote setpoint value. If used, will be linked to an output of an upstream block. In some blocks, may be left unlinked, and a local setpoint value (typically SP) will be used instead.

CAS_IN_D
A remote setpoint value. If used, will be linked to an output of an upstream block. In some blocks, may be left unlinked, and a local setpoint value (typically SP_D) will be used instead.

CHANNEL
Used by I/O function blocks to select a physical I/O channel. This mapping is defined by the manufacturer. In the FP-3000, this parameter is automatically updated when the FIELDPOINT_MODULE and FIELDPOINT_CHANNEL parameters are modified.

CLR_FSTATE
Writing Clear to this parameter causes the device-wide faultstate to be cleared and output blocks to resume normal execution. Also see SET_FSTATE and FAULT_STATE parameters.

CONFIRM_TIME
The lower bound on the time the device waits to send alert report messages if no confirmation is received from a host.

CONTROL_OPTS
A list of options used to adjust the way control blocks, such as the PID block, operate. The options are described in the following table.


Control Options
Options
Description
Bypass Enable If set, lets you set the BYPASS parameter and bypass the algorithm’s control.
SP-PV Track in Man Causes the setpoint to track the process variable in Man.
SP-PV Track in ROut Causes the setpoint to track the process variable in ROut.
SP-PV Track in LO or IMan Causes the setpoint to track the process variable in LO or IMan.
SP Track Retained Target Causes the setpoint to track the input value of the retained target of the block. The retained target of the block is the lowest priority mode set in the target mode field of the MODE_BLK parameter of the block. For example, if the RCas bit is set in the target mode, the setpoint tracks RCAS_IN.
Direct Acting Defines the relationship between changes to the PV and changes to the output. For example, consider a case with a fixed SP while the process variable varies. When Direct Acting is set, an increase in the process variable causes the control block's output value to be increased. When Direct Acting is clear, a increase in the process variable causes the control block's output value to be decreased.
Track Enable Enables external tracking. If Track Enable is true, and TRK_IN_D is true, TRK_VAL overwrites the value at the output of the block except when Man is the target mode.
Track in Manual Enables tracking in Manual mode.
Use PV for BKCAL_OUT When set, uses the process variable as the value for BKCAL_OUT, instead of the setpoint.
Obey SP Limits if Cas or RCas When set, confines the setpoint to values within SP_HI_LIM and SP_LO_LIM, even when the setpoint comes from another function block.
No OUT Limits in Man Unused in FieldPoint.


CYCLE_SEL
Identifies the block execution methods available. Unused in National Instruments FP-3000.

CYCLE_TYPE
Used to select the block execution method. Unused in National Instruments FP-3000.

DD_RESOURCE
Unused in FieldPoint.

DD_REV
The revision of the device description used by the device.

DEV_REV
The revision of the device.

DEV_TYPE
The manufacturer’s model number for the device.

DISC_ALM
The current state of the discrete alarm, along with a time and date stamp.

DISC_LIM
The discrete input state in which an alarm should be generated.

DISC_PRI
Priority of the discrete alarm.

DV_HI_ALM
The current state of the deviation high alarm, along with a time and date stamp.

DV_HI_LIM
The deviation limit between the PID block setpoint and process value, in engineering units, beyond which the deviation high alarm is considered active.

DV_HI_PRI
The priority of the deviation high alarm.

DV_LO_ALM
The current state of the deviation low alarm, along with a time and date stamp.

DV_LO_LIM
The deviation limit between the PID block setpoint and process value, in engineering units, beyond which the deviation low alarm is considered active.

DV_LO_PRI
The priority of the deviation low alarm.

FAULT_STATE
The current status of the device faultstate. It can be set and cleared with SET_FSTATE and CLR_FSTATE. If it is set, all output blocks in the device initiate their own faultstate behavior.

FEATURE_SEL/FEATURES
The FEATURES parameter lists features supported by the device. Use the FEATURE_SEL parameter to manually enable and disable the supported features listed in the FEATURES parameter. The features are listed in the following table.


Feature Parameter Options
Option
Description
Unicode The device supports strings in Unicode format. The FP-3000 does not support this feature.
Reports The device supports event report messages for alarming. If this feature is not selected in the FEATURE_SEL parameter, the FP-3000 continues to detect alarms and events, but does not report them over the bus. In this case, the host must poll the alarm parameters to detect alarm conditions as they change.
Faultstate The device supports Faultstate behavior for output blocks.
Soft Write Lock The device supports locking of configuration of parameters with the WRITE_LOCK parameter in the resource block. With this feature selected and the WRITE_LOCK parameter written to “set,” writes to all static configuration parameters are disallowed.
Hard Write Lock The device supports locking of configuration parameters. For the FP-3000, a switch on the back of the device must also be set. If Hard Write Lock is enabled, the switch disallows writes to all configuration parameters in the device, including FEATURE_SEL.
Out Readback The device provides a way for the action of output transducers to be verified through a readback. The FP-3000 does not support this feature.
Direct Write The device provides a manufacturer-specific way to directly write to I/O channels. The FP-3000 does not support this feature.


FF_GAIN
The gain by which the feed-forward input is multiplied before it is added to the output value of the control block.

FF_SCALE
The scaling parameter used by the feed-forward value of the block.

FF_VAL
The feed-forward value.

FIELD_VAL
The value from the input channel, in percent of scale.

FIELD_VAL_D
The value from the discrete input channel.

FREE_SPACE
The percentage of memory available on the device. This can be used when instantiating blocks to determine the remaining capacity of the FP-3000. This value will be zero in preconfigured devices since they do not allow user configuration.

FREE_TIME
Percentage of block processing time that is available to process additional blocks. Unused in FieldPoint.

FSTATE_TIME
Time in seconds to delay from the detection of loss of communications with the host for the output block remotes setpoint until the enaction of the fault state output.

FSTATE_VAL
The setpoint value to be used on failure. Note: The I/O option Failsafe to value must be selected.

FSTATE_VAL_D
The discrete setpoint value to be used on failure. Note: The I/O option Failsafe to value must be selected.

Fieldbus Parameters G-L


GAIN
The gain constant used by the PID in calculating the proportional component of the output.

GRANT_DENY
Allows HMI applications to determine access privileges for block parameters.
Note: The device does not use this parameter to restrict parameter access itself. It is only for the benefit of host applications.

HARD_TYPES
A list of available channel types. As I/O modules are inserted and removed from the FP-3000 bank, bits in this field change to reflect the presence or absence of types of I/O channels.


Hard Types
Bitmask
Description
Analog Input This bit is set if the FP-3000 has analog input channels available.
Analog Output This bit is set if the FP-3000 has analog output channels available.
Discrete Input This bit is set if the FP-3000 has discrete input channels available.
Discrete Output This bit is set if the FP-3000 has discrete output channels available.


HI_ALM
The current state of the high alarm, along with a time and date stamp.

HI_HI_ALM
The current state of the high-high alarm, along with a time and date stamp.

HI_HI_LIM
The limit, in PV units, beyond which the high-high limit alarm is considered active.

HI_HI_PRI
The priority of the high-high limit alarm.

HI_LIM
The limit, in PV units, beyond which the high limit alarm is considered active.

HI_PRI
The priority of the high limit alarm.

IN
The primary input of the block.

IN_1
The secondary input of the block.

IO_OPTS
A bitmask used to adjust the way I/O blocks (AI, DI, AO, and DO) operate. The following table describes the operation bitmasks.


Operation Bitmasks
Bitmask
Description
Invert In discrete blocks, this maps a physical state of Discret_State_0 to Discret_State_1 and maps every other physical transducer state to Discret_State_0.
SP-PV Track in Man Causes the setpoint to track the process variable in Man.
SP-PV Track in LO or IMan Causes the setpoint to track the process variable in LO or IMan.
SP Track Retained Target Causes the setpoint to track the input value of the retained target of the block. The retained target of the block is the lowest priority mode set in the target mode field of the MODE_BLK parameter of the block. For example, if the RCas bit is set in the target mode, the setpoint tracks RCAS_IN. For a list of modes in priority order, see the article on Mode Shedding.
Increase to Close Remaps the block’s scaling so that as the input increases, the output decreases.
Faultstate to Value When set, the block’s faultstate behavior sets the output value to the value in FSTATE_VAL. When clear, the block’s faultstate behavior leaves the output value at its current setting.
Use Faultstate Value on Restart When set, causes the output value of output blocks to go to faultstate value immediately after a device restart. When clear, uses the value in nonvolatile memory.
Target to Man if Faultstate Active When set, sets the target mode of the block to manual mode when faultstate goes active.
Use PV for BKCAL_OUT When set, uses the process variable as the value for BKCAL_OUT, instead of the setpoint.
Low Cutoff When set, enables the AI low cutoff parameter.


ITK_VER
The version of the Interoperability Test Kit with which this device was tested.

L_TYPE
The linearization type. This parameter affects the way the value from the transducer is linearized in the analog input block before it is presented as the block output. In all cases, the FIELD_VAL parameter behaves as follows:

FIELD_VAL = 100 * (transducer_value - XD_SCALE.EU0) / (XD_SCALE.EU100 - XD_SCALE.EU0)

FIELD_VAL can be simply described as the percentage of span reading from the transducer, and therefore its units are percent.


Linearization Types
Type
Description
Direct The block output is directly taken from the transducer value:
OUT = transducer_value
Indirect The block output is scaled according to OUT_SCALE from the value in FIELD_VAL:
OUT = OUT_SCALE.EU0 + ((FIELD_VAL/100) * (OUT_SCALE.EU100 - OUT_SCALE.EU0))
Indirect Square Root The block output is scaled according to OUT_SCALE from the value in FIELD_VAL. Before the field value is rescaled, the square root is taken.
OUT = OUT_SCALE.EU0 +
(SQRT(FIELD_VAL / 100) * (OUT_SCALE.EU100 - OUT_SCALE.EU0))
Uninitialized An invalid setting. The device reports a configuration error with an Uninitalized L_TYPE.


LIM_NOTIFY
A limit on the number of unconfirmed alarm/event notification messages the device can have active at once. This must be less than or equal to MAX_NOTIFY.

LO_ALM
The current state of the low alarm, along with a time and date stamp.

LO_LIM
The limit, in PV units, beyond which the low limit alarm is considered active.

LO_LO_ALM
The current state of the low-low alarm, along with a time and date stamp.

LO_LO_LIM
The limit, in PV units, beyond which the low-low limit alarm is considered active.

LO_LO_PRI
The priority of the low-low limit alarm.

LO_PRI
The priority of the low limit alarm.

LOW_CUT
With an L_TYPE of Indirect Square Root, this can be used to establish a floor (in percent of scale) for values from the transducer. Values below this floor are considered to be zero. This feature must first be enabled by setting Low Cutoff in the IO_OPTS parameter.

Fieldbus Parameters M-P


MANUFAC_ID
The ID of the manufacturer of the device. For National Instruments devices, it is 0x4E4943. The parameters MANUFAC_ID, DEV_TYPE, DEV_REV, and DD_REV are used in combination for a host tool to locate the Device Description for this device.

MAX_NOTIFY
The maximum number of unconfirmed alarm/event notification messages the device supports.

MEMORY_SIZE
Unused by FieldPoint.

MIN_CYCLE_T
The length of the shortest macrocycle the device supports.

MODE_BLK
Sets the operational and permitted modes of the block. The following table describes the operational and permitted modes of the block.


Operational Modes
Mode
Description
Target The desired mode of operation of the block. This field is writable. Several bits may be set in this field, and typically, the highest priority bit that is set will be considered to be the target mode. O/S is the highest priority bit.
Out of Service (O/S). The block is out of service, block execution is suspended, and all output parameters take a status of Bad::OutOfService.
Initialization Manual (IMan). The block is in the process of initializing a cascade. This is used for upstream (control) blocks when they are initializing for smooth transfer into Automatic mode. This is not a valid target mode, but it is a valid actual mode.
Local Override (LO). Faultstate or an interlock is active and causing the output value of the block to be overridden. This is not a valid target mode, but is a valid actual mode.
Manual (Man). The output value of the block is set by the user.
Auto (Auto). The output value of the block is set by the block algorithm, and the block is using a local value for its setpoint.
Cascade (Cas). The setpoint for the block is taken from the CAS_IN parameter, which is typically connected to the output of another block. This mode cannot be entered before cascade initialization takes place. When Cascade desired as a target mode, the Auto bit is also set in the target.
Remote Cascade (RCas). Like Cascade mode, in Remote Cascade mode the setpoint of the block comes from an outside data source. Unlike Cascade mode, in Remote Cascade mode the setpoint is sourced from the RCAS_IN parameter, which is written by a host application and not another function block.
Remote Output (ROut). Remote Output mode is analogous to Remote Cascade mode, except that the remote host application directly sets the output of the block and not the setpoint. In the case of an analog output block, this bypasses setpoint rate and absolute limiting.
Actual A bit reflecting the current state of operation of the block. This is a read-only field. Only one bit will be set at a time by the block. Actual mode is a function of the target mode and the current conditions in which the block is executing. Several conditions (such as cascade initialization or fault state conditions) can cause the actual mode to differ from the target mode.
Permitted A bitmask indicating which modes are permitted target modes and which are not. This field is writable. This could be used by the plant operator to disallow certain modes the block would normally be permitted to have as a target mode.
Normal Not used by the block, this can be used by an operator to store the normal mode of operation for the block in normal plant operations. This field is writable. Used by the NI Configuration Tool to set the Target mode after download when the "Automatic Mode Handling" feature is in effect.


NV_CYCLE_T
The regular time interval, in milliseconds, at which nonvolatile parameters are committed to nonvolatile storage. A value of zero means that the parameters are never written to nonvolatile memory. Note that nonvolatile parameters are stored to nonvolatile memory when they are changed by a user over the network. The NV_CYCLE_T parameter sets the rate at which changes caused by the device itself are stored to nonvolatile memory.

OUT
The current output value of the block.

OUT_D
The current output value of a discrete block.

OUT_HI_LIM
A limit for the maximum output value from a block in modes other than manual.

OUT_LO_LIM
A limit for the minimum output value from a block in modes other than manual.

OUT_SCALE
The scaling parameter used for the output parameter.


OUT_SCALE Parameter
Subfield
Meaning
EU_100 Engineering units value at 100 percent of scale.
EU_0 Engineering units value at zero percent of scale.
UNIT_INDEX Actual engineering units code (such as mA).
DECIMAL Number of digits a host shows to the right of the decimal for display purposes.


OUT_STATE
Index to the text description of the discrete output state.

PV
The process variable, or primary variable for this block. For AI and control blocks such as PID, this represents a measurement of the state of the process (such as temperature or level). For AO blocks, the process variable is the current setpoint of the block.

PV_D
The process variable, or primary variable for this block. For DI and discrete control blocks, this represents a measurement of the discrete state of the process. For DO blocks, the process variable is the current discrete setpoint of the block.

PV_FTIME
The filter time, in seconds, used in input blocks. For analog blocks, it is the time constant for a low pass exponential filter used to damp out rapid oscillations in the input value before using it as the process variable. For discrete blocks, it is the time the PV must remain constant after a change for the change to be reported.

PV_SCALE
The scaling parameter used by the process variable of the block. Converts from percent of scale to a process variable in engineering units. Contains the same subfields as OUT_SCALE.

PV_STATE
Index to the text describing the state of a discrete PV.

Fieldbus Parameters Q-S


RA_FTIME
The filter time constant, in seconds, for the value to be used in the ratio.

RATE
The time constant for the derivative component of the PID block. A zero disables the derivative term. The units are seconds.

RCAS_IN
The cascade input for a control or output block set by a remote host. This is propagated to the setpoint of the block when it is in RCas mode. If the block is in RCas mode and this parameter is not updated in SHED_RCAS time (a parameter in the resource block), the block enters mode shedding. Mode shedding allows the block to degrade from RCas mode into some higher priority mode. Refer to the article on mode shedding for more information.

RCAS_IN_D
The discrete cascade input for a control or output block set by a remote host. This is propagated to the setpoint of the block when it is in RCas mode. If the block is in RCas mode and this parameter is not updated in SHED_RCAS time (a parameter in the resource block), the block enters mode shedding. Mode shedding allows the block to degrade from RCas mode into some higher priority mode. Refer to the article on mode shedding for more information.

RCAS_OUT
The back calculation output used by the supervisory host when establishing a Remote cascade loop.

RCAS_OUT_D
The discrete back calculation output used by the supervisory host when establishing a Remote cascade loop.

READBACK
The valve or actuator position read back from the transducer, in transducer units.

READBACK_D
The transducer state for the actual discrete valve or actuator position.

RESET
The time constant for the integral component of the PID block. It is measured in seconds per repeat (so larger values have less effect, and INF effectively disables the integral term).

RESTART
Allows the user to restart the device remotely. The following table lists restart values.


Restart Values
Value
Behavior
Restart Resource Restarts the device.
Restart to Defaults Restarts the device, restoring all parameter values to default values.
Restart Processor Restarts the device as if the power was cycled.


Caution: Using Restart to Defaults causes all your configured parameters in the FP-3000 to revert to their factory default settings.

ROUT_IN
The cascade input set by a remote host. This is propagated to the output of the block when it is in ROut mode. If the block is in ROut mode and this parameter is not updated in SHED_ROUT time (a parameter in the resource block), the block enters mode shedding. Mode shedding allows the block to degrade from ROut mode into some higher priority mode. See the article on Mode Shedding for more information.

ROUT_OUT
This is the back calculation output used by the host when trying to establish a remote output loop. While the loop is being established, it is the current value of the output channel and can be used by the host to initialize for smooth transfer of control.

RS_STATE
The current state of the device. The following table lists device states.


Device States
State
Meaning
Start/Restart The device has just started a restart cycle.
Initialization The device is performing startup diagnostics.
Failure A hardware failure has been detected.
On-Line Linking The device is online and waiting for new parameter linkages to be established.
On-Line The device is online and in service.
Standby The device is online, but currently out of service.


SEL_1 through SEL_3
Input values for the selector.

SEL_TYPE
Defines the selector action - High, Medium, or Low.

SET_FSTATE
Allows the user to set the device faultstate to active. This, in turn, forces all output blocks into their own faultstate behavior.

SHED_OPT
Controls the way blocks enter mode shedding. Each option listed below has a companion No Return option. The No Return shedding options change the target mode of the device to the shed mode and prevent the device from re-entering RCas or ROut mode after the shed condition has ended. The following table lists shed conditions. Refer to the article on Mode Shedding for more information.


Shed Conditions
Shed Mode
Behavior
Normal Shed The block sheds into the next higher priority mode set in the permitted mode field of MODE_BLK.
Shed to Auto The block sheds into automatic mode.
Shed to Manual The block sheds into manual mode.
Shed to Retained The block sheds to the next higher priority mode set in the target mode field of MODE_BLK.


SHED_RCAS
The shed time for the RCAS_IN parameter. If the block is in RCas mode and the RCAS_IN parameter has not been updated in SHED_RCAS time, the block performs mode shedding as determined by the SHED_OPT parameter.

SHED_ROUT
The shed time for the ROUT_IN parameter. If the block is in RCas mode and the ROUT_IN parameter has not been updated in SHED_RCAS time, the block performs mode shedding as determined by the SHED_OPT parameter.

SIMULATE
Used to bypass the physical I/O channel and allow the block to operate normally, using a simulated I/O channel. For this feature to be enabled on an FP-3000, you must set a switch on the back of the device. To see how to configure the switch, refer to the FP-3000 manual.

SIMULATE_D
Used to bypass the physical I/O channel and allow the block to operate normally, using a simulated discrete I/O channel. For this feature to be enabled on an FP-3000, you must set a switch on the back of the device. To see how to configure the switch, refer to the FP-3000 manual.

SP
The analog setpoint.

SP_D
The discrete setpoint.

SP_HI_LIM
The upper limit on an operator-entered setpoint for the block. If the operator enters a setpoint that exceeds this value, the setpoint is considered to be SP_HI_LIM with a status that indicates that it is limited.

SP_LO_LIM
The lower limit on an operator-entered setpoint of the block. If the operator enters a setpoint below this value, the setpoint is considered to be SP_LO_LIM with a status that indicates that it is limited.

SP_RATE_DN
In Auto mode, the rate, in PV units per second, the setpoint can be moved downwards. If the setpoint moves faster than SP_RATE_DN, the block acts as if the setpoint is moving downwards at the maximum rate with a status bit that indicates that it is limited. If set to zero, the set point is used immediately.

SP_RATE_UP
In Auto mode, the rate, in PV units per second, the setpoint can be moved upwards. If the setpoint moves faster than SP_RATE_UP, the block acts as if the setpoint is moving upwards at the maximum rate with a status bit that indicates that it is limited. If set to zero, the set point is used immediately.

ST_REV
ST_REV is incremented by one each time a static parameter is modified.

STATUS_OPTS
A collection of options that affect the status behavior of the block. The following table lists the status options.


Status Options
Option
Meaning
IFS if Bad IN Set the status of the block output to initiate faultstate if the IN parameter goes bad.
IFS if Bad CAS_IN Set the status of the block output to initiate faultstate if the CAS_IN parameter goes bad.
Use Uncertain as Good If set, blocks will treat the Uncertain status on an input parameter as if it were a Good status. If clear, Uncertain status is treated as Bad.
Propagate Failure Forward If the status of the IN parameter of the block is Bad::Device_Failure or Bad::Sensor_Failure, the failure will be propagated to the OUT parameter. No alarm will be generated.
Propagate Failure Backward If the status at BKCAL_IN or from the physical I/O channel is bad, the failure will be propagated to the BKCAL_OUT parameter. No alarm will be generated.
Target to Manual if Bad IN Set the target mode of the block to Man if the IN parameter has a bad status.
Uncertain if Limited For input or calculation blocks, the output status will be set to Uncertain if the transducer or calculated value is limited (i.e., at its high or low limit).
Bad if Limited Set the output status to Bad if the transducer value is limited (i.e., at its high or low limit).
Uncertain if Manual Mode Set the output status to Uncertain if the block is in Man mode.
Do Not Select if Not Auto Mode Set the output status to Do Not Select if the block is not in an actual mode of Auto, CAS or RCas and not initializing. This is useful for blocks upstream of the selector block.
Do Not Select if Not Cas Mode Set the output status to Do Not Select if the block is not in an actual mode of CAS or RCas and is not initializing. This is useful for blocks connected to a selector block.


STRATEGY
Used to identify groupings of blocks. Not used by the block itself.

 

Fieldbus Parameters T-Z


TAG_DESC
User description for the purpose of the block.

TEST_RW
Unused by the block algorithm. Used to test interoperability of reads and writes of different parameter types.

TRK_IN_D
Used to enable tracking of the output value to TRK_VAL. When this is true, the output value of the block takes on the value specified in TRK_VAL.

TRK_SCALE
The scaling parameter used for the value specified by TRK_VAL.

TRK_VAL
The value the block will track when tracking is enabled by TRK_IN_D.

UPDATE_EVT
The current state of the update event, along with a time and date stamp. This event is issued whenever a static parameter is changed and ST_REV is incremented. The index information for the parameter that changed and the new value of ST_REV is included in the alert.

WRITE_ALM
State of the alert generated if WRITE_LOCK is cleared, along with a time and date stamp.

WRITE_LOCK
The software write lock for the device. When this is set to true, writes to all configuration parameters of all blocks are disallowed. The WRITE_ALM block alarm is active when writes are allowed and clear when they are disallowed.

WRITE_PRI
The priority of the write alarm.

XD_SCALE
The scaling parameter used to interpret values from the physical I/O channel. This is used to translate from a physical transducer value to a percent of scale.


Scaling Parameter Values
Subfield
Meaning
EU_100 Engineering units value at 100 percent of scale.
EU_0 Engineering units value at zero percent of scale.
UNIT_INDEX Actual engineering units code (such as mA).
DECIMAL Number of digits a host shows to the right of the decimal for display purposes. (Not used by the NI-FBUS Configurator.)


XD_STATE
Index to the text description of the transducer state.