SIS function blocks > SIS Logical Blocks > Logic Solver Alarm function block

Logic Solver Alarm function block parameters

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

Table: LSALM Function Block System Parameters

Parameter

(Data Type)

Default Value

(Units)

Characteristics

Description

ALM_ACT

(Alarm)

0

NVM:

Preserved on Download

Alarm condition state:

  • 0 = Inactive

  • 1 = Active

ALM_DELAY_OFF

(Floating point)

0

(Seconds)

Access:

Configurable, Tuning

NVM:

Restored on Restart

The length of time IN must stay at a value sufficient to clear the alarm condition before ALM_ACT becomes Inactive (0).

ALM_DELAY_ON

(Floating point)

0

(Seconds)

Access:

Configurable, Tuning

NVM:

Restored on Restart

The length of time IN must stay at a value sufficient to set the alarm condition before ALM_ACT becomes Active (1).

ALM_ENAB

(Discrete with status)

1

Access:

Configurable, Tuning

NVM:

Restored on Restart

Enables alarm condition detection:

  • 1 = Enabled

  • 0 = Disabled

ALM_ENAB_DELAY

(Floating point)

0

(Seconds)

Access:

Configurable, Tuning

NVM:

Restored on Restart

The length of time after ALM_ENB is set to Enabled (1) before alarm processing begins.

ALM_HYS

(Floating point)

0.5

(Percent of IN_SCALE)

Access:

Configurable, Tuning

NVM:

Restored on Restart

Alarm hysteresis. The minimum amount IN must change and be on the inactive side of ALM_LIM before an active alarm becomes inactive.

ALM_LIM

(Floating point)

0

(EU of IN_SCALE)

Access:

Configurable, Tuning

NVM:

Restored on Restart

The value compared to IN to determine if an alarm condition exists.

ALM_TIMER

(Floating point)

0

(seconds)

NVM:

Preserved on Download

Timer for the ALM_DELAY_OFF, ALM_DELAY_ON, and ALM_ENAB_DELAY parameters.

ALM_TYPE

(Named Set)

High

Access:

Configurable, Tuning

NVM:

Restored on Restart

Alarm detection type (High or Low). If High, alarm is active when IN is greater than ALM_LIM. If Low, alarm is active when IN is less than ALM_LIM.

IN

(Floating point with status)

0

(EU of IN_SCALE)

Access:

Tuning

NVM:

Restored on Restart

Input value on which alarm detection occurs.

IN_SCALE

(Scaling)

0.0 to 100.0

Access:

Configurable, Tuning

NVM:

Restored on Restart

Scaling parameter for IN.