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In OPC there is a recommendation of what properties are expected to be supported by an alarm & event server. The recommended
properties are shown in Table 5-1. The column names correspond to the attributes in the Property class.
Table 5-1 Recommended Properties Table 5-1 Recommended Properties
label |
id |
canonical_ data_type |
description |
||
Condition Status | 300 | STRING_TYPE | The current alarm or condition status associated with the Item (for example, “NORMAL,? “ACTIVE,? “HI ALARM?). | ||
Alarm Quick Help | 301 | STRING_TYPE | A short text string providing a brief set of instructions for the operator to follow when this alarm occurs. | ||
Alarm Area List | 302 | STRING_TYPE sequence | An array of strings indicating the plant or alarm areas that include this ItemID. | ||
Primary Alarm Area | 303 | STRING_TYPE | A string indicating the primary plant or alarm area including this ItemID. | ||
Condition Logic | 304 | STRING_TYPE | An arbitrary string describing the test being performed (for example, “High Limit Exceeded? or “TAG.PV >= TAG.HILIM?). Refer to Section 5.2.7.3, “Condition Logic,? on page 5-38. |
Limit ExceededDeadbandHiHi LimitHi LimitLo LimitLoLo LimitRate of Change LimitDeviation Limit |
|||||
305 | STRING_TYPE | For multistate alarms, the condition exceeded (for example, HIHI, HI, LO, LOLO). | |||
306 | DOUBLE_TYPE | Deadband | |||
307 | DOUBLE_TYPE | HiHi Limit | |||
308 | DOUBLE_TYPE | Hi Limit | |||
309 | DOUBLE_TYPE | Lo Limit | |||
310 | DOUBLE_TYPE | LoLo Limit | |||
311 | DOUBLE_TYPE | Rate of Change Limit | |||
312 | DOUBLE_TYPE | Deviation Limit | |||
3124999 | Reserved by OPC |