OPC Alarm and Event Data

OPC alarm event categories are made available to subscribing alarm clients (in AlarmWorX64 Viewer, GraphWorX64 displays, and other runtime access tools). The information provided in this topic is helpful when working with Alarm Categories.

 

Below in this topic are:

Events and Their Attributes

This table shows the different event types, their names, and their attributes.

 

Alarm Event Attributes

Event Name

Deviation

Digital

Limit

Rate of Change

Type

Comment

ACK COMMENT

VT_BSTR

Comment entered when alarm was last acknowledged.

ALARM COUNT

VT_I4

Number of alarm transitions before acknowledge.

AREA

VT_ARRAY | VT_BSTR

Array of areas.

CV

VT_R8

Current Value (OPC Input 1 or 2).

DEADBAND

 

VT_BOOL

Alarm detection Deadband.

DEFAULT DISPLAY

VT_R8

A text string, usually a file name, that when launched provides related information.

HELP TEXT

VT_BSTR

Help information.

LIMIT VALUE EXCEEDED

 

VT_BSTR

The Current Value at the time the limit was exceeded.

LOOP DESC

VT_R8

A description of the Source (tag).

NEXT_LIM

 

VT_BSTR

The value of the next limit.

NORMAL STATE

 

 

 

VT_R8

Value of the normal state (TRUE or FALSE).

PREV LIM

 

 

VT_BOOL

Value of the previous limit reached.

RELATED VALUE 01-10

VT_R8

Associates up to 10 OPC tags or expressions with each alarm tag as ”r;supplemental” information to the alarm.

SP

 

 

 

VT_SP

Setpoint (OPC Input 2)

OPC Data Access Interface

The AlarmWorX64 Server exposes much of its real-time and configuration data via the OPC Data Access specification. This allows OPC Data Access client applications, such as GraphWorX64 , to make use of alarm-related data without using the OPC Alarm & Events interface. Some typical uses would include:

The following table lists the OPC item names that are available from the server.

 

OPC Data Access Items

Item Name

Type

Read/Write

Comment

Active

VT_BOOL

R

Tag's Global Alarm Active Bit.

Name

VT_BSTR

R

Tag Name (Source).

Input1

VT_BSTR

R

 

BaseText

VT_BSTR

R

 

Enabled

VT_BOOL

R

Enabled state of the Source (tag).

HelpText

VT_BSTR

R

 

LIM_RTNText

VT_BSTR

R

 

LIM_Input2

VT_R8

R

 

LIM_Deadband

VT_R8

R

 

LIM_Active

VT_BOOL

R

 

LIM_Acked

VT_BOOL

R/W

 

LIM_HIHI_Active

VT_BOOL

R

 

LIM_HIHI_Enabled

VT_BOOL

R/W

 

LIM_HIHI_RequiresAck

VT_BOOL

R/W

 

LIM_HIHI_Severity

VT_R8

R/W

 

LIM_HIHI_Limit

VT_R8

R/W

 

LIM_HIHI_MsgText

VT_BSTR

R/W

 

LIM_HI_Active

VT_BOOL

R

 

LIM_HI_Enabled

VT_BOOL

R/W

 

LIM_HI_RequiresAck

VT_BOOL

R/W

 

LIM_HI_Severity

VT_R8

R/W

 

LIM_HI_Limit

VT_R8

R/W

 

LIM_HI_MsgText

VT_BSTR

R/W

 

LIM_LOLO_Active

VT_BOOL

R

 

LIM_LOLO_Enabled

VT_BOOL

R/W

 

LIM_LOLO_RequiresAck

VT_BOOL

R/W

 

LIM_LOLO_Severity

VT_R8

R/W

 

LIM_LOLO_Limit

VT_R8

R/W

 

LIM_LOLO_MsgText

VT_BSTR

R/W

 

LIM_LO_Active

VT_BOOL

R

 

LIM_LO_Enabled

VT_BOOL

R/W

 

LIM_LO_RequiresAck

VT_BOOL

R/W

 

LIM_LO_Severity

VT_R8

R/W

 

LIM_LO_Limit

VT_R8

R/W

 

LIM_LO_MsgText

VT_BSTR

R/W

 

DEV_RTNText

VT_BSTR

R

 

DEV_Input2

VT_R8

R

 

DEV_Deadband

VT_R8

R

 

DEV_Active

VT_BOOL

R

 

DEV_Acked

VT_BOOL

R/W

 

DEV_HIHI_Enabled

VT_BOOL

R/W

 

DEV_HIHI_RequiresAck

VT_BOOL

R/W

 

DEV_HIHI_Severity

VT_R8

R/W

 

DEV_HIHI_Limit

VT_R8

R/W

 

DEV_HIHI_MsgText

VT_BSTR

R/W

 

DEV_HI_Enabled

VT_BOOL

R/W

 

DEV_HI_RequiresAck

VT_BOOL

R/W

 

DEV_HI_Severity

VT_R8

R/W

 

DEV_HI_Limit

VT_R8

R/W

 

DEV_HI_MsgText

VT_BSTR

R/W

 

DEV_LOLO_Enabled

VT_BOOL

R/W

 

DEV_LOLO_RequiresAck

VT_BOOL

R/W

 

DEV_LOLO_Severity

VT_R8

R/W

 

DEV_LOLO_Limit

VT_R8

R/W

 

DEV_LOLO_MsgText

VT_BSTR

R/W

 

DEV_LO_Enabled

VT_BOOL

R/W

 

DEV_LO_RequiresAck

VT_BOOL

R/W

 

DEV_LO_Severity

VT_R8 R/W

R/W

 

DEV_LO_Limit

VT_R8 R/W

R/W

 

DEV_LO_MsgText

VT_BSTR

R/W

 

DIG_RTNText

VT_R8 R/W

R

 

DIG_Input2

VT_R8

R

 

DIG_Active

VT_BOOL

R

 

DIG_Acked

VT_BOOL

R/W

 

DIG_Enabled

VT_BOOL

R/W

 

DIG_RequiresAck

VT_BOOL

R/W

 

DIG_Severity

VT_R8

R/W

 

DIG_Limit

VT_R8

R/W

 

DIG_MsgText

VT_BSTR

R/W

 

ROC_RTNText

VT_BSTR

R

 

ROC_Input2

VT_R8

R

 

ROC_Active

VT_BOOL

R

 

ROC_Acked

VT_BOOL

R/W

 

ROC_Enabled

VT_BOOL

R/W

 

ROC_RequiresAck

VT_BOOL

R/W

 

ROC_Severity

VT_R8

R/W

 

ROC_Limit

VT_R8

R/W

 

ROC_MsgText

VT_BSTR

R/W

 

LIM_HIHI_Active

VT_BOOL

R

 

LIM_HI_Active

VT_BOOL

R

 

LIM_LOLO_Active

VT_BOOL

R

 

LIM_LO_Active

VT_BOOL

R

 

DEV_HIHI_Active

VT_BOOL

 

 

DEV_HI_Active

VT_BOOL

 

 

DEV_LOLO_Active

VT_BOOL

 

 

DEV_LO_Active

VT_BOOL

 

 

 

Area Bits

Item Name

Type

Read/Write

Comment

Area_Active

VT_BOOL

R

Notifies that one or more tags in the current area is in active state.

Area_Unacked

VT_BOOL

R

Notifies that one or more tags in the current area has not been acknowledged.

Recursive_Active

VT_BOOL

R

Notifies that one or more tags in the current area or any subdirectories is in active state.

Recursive_Unacked

VT_BOOL

R

Notifies that one or more tags in the current area or any subdirectories has not been acknowledged.

Error Reporting

Internal errors encountered by the AlarmWorX64 Server are reported via the GENESIS64 Event Server, another OPC Alarm & Events compliant server. The GENESIS64 Event Server can optionally write selected events to the NT Event Log. The following simple events may be generated by the AlarmWorX64 Server : For the GENESIS64 Event Server, severity values of 600 and below are considered "normal," and severity values of 601 to 1000 are considered errors.

 

Server Errors

Severity

Message

500

"%1 %2 Started."

500

"%1 %2 Stopped."

700

"Alarm Tag: %1, Condition: %2, Input Item: %3, Error: Unknown"

700

"Alarm Tag: %1, Condition: %2, Input Item: %3, Error: Tag does not exist."

700

"Alarm Tag: %1, Condition: %2, Input Item: %3, Error: Rejected by Security Server ."

700

"Alarm Tag: %1, Condition: %2, Input Item: %3, Error: Licensed I/O Point Count Exceeded. "

700

"Alarm Tag: %1, Condition: %2, Input Item: %3, Error: Demo mode has timed out."

700

"Alarm Tag: %1, Condition: %2, Input Item: %3, Error: Local I/O not allowed on Browser node."

700

"Alarm Tag: %1, Condition: %2, Input Item: %3, Error: COM error registering with GenRegistrar."

800

"%1 %2 Failed to Register with GenRegistrar. Reason: %3"

800

"No configuration found for node and no ""Default"" configuration in Database Provider: %1 Connection:  %2"

800

"Database Error - Provider: %1 Connection: %2"