SIS function blocks > SIS Advanced Function Blocks > Logic Solver State Transition Diagram function block

Logic Solver State Transition Diagram function block parameters

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

Table: LSSTD Function Block System Parameters

Parameter

(Data Type)

Default Value

Characteristics

Description

DESC_INn

(String)

None

None

Configured label for transition input IN_Dn. As many as 40 characters.

ENABLE

(Boolean)

True

Access:

Tuning (SLS 1508 and CSLS major revision 1)

Operating (CSLS major revision 2 or higher)

NVM:

Preserved on Download

If ENABLE is False, STATE is set to Disabled (0). When ENABLE is set to True, STATE is forced to the initial state value (state 1).

IN_Dn

(Discrete with status)

0

Access:

Tuning (SLS 1508 and CSLS major revision 1)

Operating (CSLS major revision 2 or higher

NVM:

Restored on Restart

Transition value. A 1 indicates the transition is active and can cause a state change.

MATRIX

(16-bit unsigned integer matrix)

None

Access:

Configurable

Holds the next state values for each state/transition combination.

OUT_Dn

(Discrete with status)

0

NVM:

Preserved on Download

The discrete value with status for each configured state.

OVERRIDE

(Named Set)

None

NVM:

Preserved on Download

Indicates when and how the normal logic is being overridden. Choices are:

  • None

  • All Associated Transitions Masked

  • State Forced.

RESET_STATE

(Boolean)

False

Access:

Tuning (SLS 1508 and CSLS major revision 1)

Operating (CSLS major revision 2 or higher)

NVM:

Preserved on Download

Forces the block to the initial state (state 1).

STATE

(Named Set)

Disabled

Access:

Configurable

NVM:

Preserved on Download

Text indicating the current state, a value from the named set you define for this block. The default named state for LSSTD blocks is $std_seq_states.

STATE_IN

(8-bit unsigned integer)

1

Access:

Tuning

NVM:

Preserved on Download

If STATE_IN_D is 1, STATE is set to the named set value corresponding to STATE_IN's value.

The valid range for STATE_IN is 0 through the number of states configured.

STATE_IN_D

(Discrete with status)

0

Access:

Tuning

NVM:

Preserved on Download

If STATE_IN_D is 1, STATE is set to the value of  STATE_IN.

STATUS_OPT

(Named Set)

Always Use Value

Access:

Configurable, Tuning

NVM:

Restored on Restart

Determines the block's behavior when the status of a particular input is Bad. Choices are:

  • Always Use Value

  • Ignore if Bad

  • Use Last Good Value.

TERMINAL

(Boolean)

False

NVM:

Preserved on Download

If all entries in MATRIX for the current state are zero (no next state configured) or if masked transitions prevent transition to another state, then the TERMINAL parameter is set to True.

TRANSITION_MASK

(16-bit unsigned integer)

0

Access:

Tuning (SLS 1508 and CSLS major revision 1)

Operating (CSLS major revision 2 or higher)

NVM:

Restored on Restart

Integer representing a bitstring. Setting bits in TRANSITION_MASK to 1 prevents the corresponding transition from being seen as active regardless of its value or status.

VALID_TRANS

(16-bit unsigned integer)

0

Access:

Configurable

NVM:

Preserved on Download

An integer representing the bitstring that indicates the transitions that are possible from the current state. Any transitions masked by TRANSITION_MASK are not included.