SIS function blocks > SIS Advanced Function Blocks > Logic Solver Cause and Effect Matrix function block

Logic Solver Cause and Effect Matrix function block parameters

The following table lists the system parameters for the function block:

Table: LSCEM Function Block System Parameters

Parameter

(Data Type)

Default Value

(Units)

Characteristics

Description

ACTIVE_CAUSESn

(16-bit unsigned integer)

0

NVM:

Preserved on Download

Indicates which of the causes associated with an effect are currently active (0).

CAUSEn

(Discrete with status)

0

Access:

Tuning

Input parameter. Indicates an inactive (1) or active (0) process trip condition. CAUSEn is extensible from 1 to 16. The default count is 4.

CAUSE_MASK

(16-bit unsigned integer)

0

Access:

Tuning

NVM:

Preserved on Download

Bitstring used to mask causes, where 1 (True) means the corresponding cause cannot become active.

CEM_ALERTS

(Option bitstring)

None

NVM:

Preserved on Download

Contains the runtime value of alarm conditions set by the block (inactive = 0, active = 1)

  • An Effect is forced to Trip or Normal

  • An Effect has a non-zero FIRST_OUT

For a description of the alerts and information on how to access them, refer to CEM_ALERTS below this table.

DELAY_TIMEn

(Floating point)

0

(Seconds)

Access:

Configurable, Tuning

NVM:

Restored on Restart

The number of seconds before EFFECTn changes to Tripped after a trip is initiated due to an active cause.

DELAY_TIMERn

(Floating point)

0

(Seconds)

NVM:

Preserved on Download

Countdown timer for the trip delay function for EFFECTn.

DESC_CAUSEn

(String)

None

None

User-defined label for CAUSEn.

DESC_EFFECTn

(String)

None

None

User-defined label for EFFECTn.

EFFECTn

(Discrete with status)

0

NVM:

Preserved on Download

Normal (1) or Tripped (0). EFFECTn is extensible from 1 to 16. The default count is 1.

FIRST_OUTn

(16-bit unsigned integer)

0

NVM:

Preserved on Download

Indicates the cause or causes that first tripped EFFECTn.

FORCE_EFFECTn

(Named Set)

Do Not Force

Access:

Tuning (SLS 1508 and CSLS major revision 1)

Operating (CSLS major revision 2 or higher)

NVM:

Preserved on Download

The choices are:

  • Do Not Force

  • Force Trip

  • Force Normal

FORCE_OPTS

(Option bitstring)

None

Access:

Configurable, Tuning

NVM:

Restored on Restart

Configurable options for the forcing of Effects:

  • Forcing of multiple Effects is allowed

  • Force permit is not required to force Effects

  • Force permit control should be visible in operator interface

FORCE_PERMIT

(Boolean)

False

Access:

Tuning

NVM:

Preserved on Download

When a permit is required to force effects (see FORCE_OPTS), an effect can be forced only when FORCE_PERMIT is True.

LATENT_TRIP

(Boolean)

False

NVM:

Preserved on Download

When True, indicates that changing FORCE_PERMIT from True to False trips one or more effects.

MATRIX

(16-bit unsigned integer matrix)

NA

Access:

Configurable

Holds the association of causes with effects. It is configured using a grid of checkboxes to associate one or more causes with each effect.

OVERRIDESn

(Named Set)

None

NVM:

Preserved on Download

Indicates the highest priority override present on EFFECTn. The possible values are:

  • None

  • Forced to Trip

  • Forced to Normal

  • All associated Causes masked

REPORT_OPTS

(Option bitstring)

None

Access:

Configurable, Tuning

NVM:

Restored on Restart

Configurable options for block reporting:

  • Alarm conditions do not roll up to module level.

  • Event records are not generated.

These options apply only to block alarms and events and not user-defined module alarms.

REQUIRE_RESETn

(Boolean)

True

Access:

Configurable, Tuning

NVM:

Restored on Restart

Determines whether an operator reset is required before EFFECTn can transition to Normal.

RESETn

(Boolean)

False

Access:

Tuning (SLS 1508 and CSLS major revision 1)

Operating (CSLS major revision 2 or higher)

NVM:

Preserved on Download

A value of True is required to transition STATEn from Ready to Reset to Waiting for Start Permit or Normal.

RESET_PERMITn

(Boolean)

True

Access:

Configurable, Tuning

NVM:

Restored on Restart

A value of True is required for STATEn to transition to Ready to Reset.

START_PERMITn

(Boolean)

True

Access:

Configurable, Tuning

NVM:

Restored on Restart

A value of True is required for STATEn to transition from Waiting for Start Permit to Normal.

STATEn

(Named Set)

Tripped

NVM:

Preserved on Download

Indicates the current state of EFFECTn:

  • Normal

  • Trip Initiated-Delayed

  • Tripped

  • Waiting for Reset Permit

  • Ready to Reset

  • Waiting for Start Permit

STATUS_OPT

(Named Set)

Always use Value

Access:

Configurable, Tuning

NVM:

Restored on Restart

Determines the behavior when the status of an input is Bad. Choices are:

  • Always use Value

  • Use Last Good Value if Bad

  • Trip if Bad

CEM_ALERTS

The following table shows the alerts that can appear for an LSCEM block, an explanation of each alert, the bit position of each alert, and how to access the alert bit from DeltaV Operate.

Bit Value

Explanation

Bit Position

Access from DeltaV Operate

An Effect is forced to Trip or Normal

Active when any effect is being forced, that is, any FORCE_EFFECTn parameter is Force Trip or Force Normal.

0

CEM_ALERTS.F_CV[1]

An Effect has a non-zero FIRST_OUT

Active when there is a non-zero FIRST_OUTn.

1

CEM_ALERTS.F_CV[2]

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