Point Status Description

(Jump directly to the extended point status, described near the end of this page)

The point status (PS) data structure consists of a 32-bit word. The first 16-bits (bits 0-16) are common for all point types. The last 16-bits depend on point type. Since the point type is included in the PS the format is easily determined.

Common Status Bits

Point Type (Bit 3-0, mask 0x0000000F)

There are currently 11 different point types defined in PICS.

Side (Bit 5-4, mask 0x00000030)

For all point types except the system point type, the side determines which physical side is providing the point. For points provided by an alternate provider (the provider bit is set), this field reflects its value before the alternate provider began providing it. This field is useful diagnosing when the two normal providers produce different values for a point.

For system points, the field defines which side status bytes are valid for the point. (See the System Point section for details.)

Provider (Bit 6, mask 0x00000040)

This bit is set if some task other then the normal provider (such as PICS Test) is providing this point. If it is reset, the normal provider is providing this point.

Data Valid (Bit 7, mask 0x00000080)

This bit is set if the data in this point record is valid. This bit is used by different task in slightly different ways, but the bit is always set when retrieved as real-time data. The archive system may store some point records with this bit reset if the point has not been provided and it is making an archival snapshot of the current values. The retrieval task will not provide these point records to any application.

Master Revision (Bits 10-8, mask 0x00000700)

These three bits are the least significant three bits of the point's master revision value in the realtime database table. When a point or any table used by that point is changed, this field is changed. When the provider gets the update to the database for this point, it will also get the master revision. Thus, when an application receives a record with a different master revision value, it knows the provider is now using the database updated values. This knowledge can be used to synchronize static database updates with the use of that data by the provider.

Subsystem Enable (Bit 11, mask 0x00000800)

Valid for Subsystem Status Points (PT_SS) only, this bit shows whether or not the subsystem is allowed to scan (and/or produce) data. When TRUE, scanning (and data production) is enabled, when false, neither scanning nor any other form of data production (like calculated points) is performed.

Alarm Hold (Bit 12, mask 0x00001000)

This bit is set by the provider when the point enters an alarm hold condition until it returns from the alarm hold condition.

Secondary Provider (Bit 13, mask 0x00002000)

This bit is only valid for computed points. It is set if at least one point going into its computation is being provided by an alternate provider or any of its points are provided by an alternate provider.

Fresh Data (Bit 14, mask 0x00004000)

This bit is set by the provider whenever a value is provided to the realtime database. There are two times when this bit might not be set when received from the realtime a for valid data: (a) when the point is being proxied by MUXCTL and (b) when the value that RTDB is holding is more than 60 seconds old.

Reserved (Bit 15, mask 0x00008000)

These bits are always set to zero.

Point Type Specific (Bits 31-16)

These 16 bits have a different format depending on the point type. Currently there are four different formats.

Analog Specific

Primary Quality Code (Bits 19-16, mask 0x000F0000)

This field has four bits, each representing a different quality of the point.

Secondary Quality Code (Bits 23-20, mask 0x00F00000)

This field has four bits, each representing a different secondary quality of the point. This field consist of a composite of the primary and secondary quality codes of all other points used in the calculation of this point. The field is computed by taking the primary and secondary quality code of each point going into the calculation and bitwise or-ing them together. The resultant 4-bit field is the secondary quality code of the point being computed. Note that a computed point may have this feature disabled if its compute provider sets the bNoF2Qual bit for it.

Engineering Units Alarm Level (Bits 27-24, mask 0x0F000000)

This field represents the engineering units alarm level computed for this point.

Validity Alarm Level (Bits 29-28, mask 0x30000000)

This field represents the validity alarm level of the point. Only scanned points can have validity limits. Validity limit checking is performed on gain-compensated raw values. The gain-compensated raw value is the product of the sum of the raw value and the raw value compensation with the points gain value.

Rate of Change Alarm Level (Bits 31-30, mask 0xC0000000)

This field represents the rate of change alarm level. Currently this is not implemented.

Digital Specific

Primary Quality Code (Bits 19-16, mask 0x000F0000)

This field has four bits, each representing a different quality of the point.

Secondary Quality Code (Bits 23-20, mask 0x00F00000)

This field has four bits, each representing a different secondary quality of the point. This field consist of a composite of the primary and secondary quality codes of all other points used in the calculation of this point. The field is computed by taking the primary and secondary quality code of each point going into the calculation and bitwise or-ing them together. The resultant 4-bit field is the secondary quality code of the point being computed. Note that a computed point may have this feature disabled if its compute provider sets the bNoF2Qual bit for it.

Engineering Units Value (Bit 24, mask 0x01000000)

This bit represents the point's engineering units value. If set, the EU value is one. If reset, it is zero.

Alarm Level (Bit 25, mask 0x02000000)

This bit represents the engineering units alarm level for the point. If it is set, the point is in alarm. If it is reset, the point is not in alarm.

Raw Value (Bit 26, mask 0x04000000)

This bit represents the scanned value for the point. If it is set, the hardware value was a one. If reset, it was a zero.

Alarm Inhibit (Bit 27, mask 0x08000000)

If alarming is disabled for this point, this bit will be TRUE (and the value of the Alarm Level bit should not be considered as meaningful)..

Reserved (Bits 31-28, mask 0xF0000000)

These bits are always set to zero.

Time Specific

Section (bits 19-16, mask 0x000F0000)

Section where this time value originated.

Reserved(bits 23-20, mask 0x00F00000)

This field must be zero.

Provider ID (bits 29-24, mask 0x3F000000)

This field determines which 8800 data provider provided this time value. A value of 0 means this time value was provided by MuxCtl since no 8800s have reported in the last second. Note that non-zero values reflect the 8800 pair, not the individual 8800 number.

Provider Side (bit 30, mask 0x40000000)

This field determines which 8800 (or MUX) side provided this time data. Zero means that side A provider the time. One means that side B provided the time.

Master (bit 31, mask 0x80000000)

When non-zero, when the time came from the master section.

System Specific

System points describe the state of one or two compute systems in the PICS network. If it describes two systems they are a redundant pair. The system specific part of the point status consists of two identically formatted parts, one for each system. Which system is described in each part is determined by the side part of the point status.

Side Format (Bits 31-24, mask 0xFF000000 or bits 23-16, mask 0x00FF0000)

The bits are labeled for Side 0. Add eight (8) to them for the Side 1 bits.

Status (Bits 19-16, mask 0x000F0000)

These bits define the current status of the system as seen by the primary system monitor for all but the 8800's. The provider of the data for 8800's is the primary Mux Control process.

Primary (Bit 20, mask 0x00100000)

This bit is set if the system is the primary system in redundant pairs or is a non-redundant system. Otherwise, it is reset.

DataLive (Bit 21, mask 0x00200000)

This bit has a slight different meaning for 8800 system points and all other systems. For the 8800's, the bit is set if the time point is valid to be used as the system time value. Otherwise, it is reset. For other systems, the bit is set if the system is receiving time updates in the real-time data. Otherwise, it is reset.

8800 Flag(Bit 22, mask 0x00400000)

This bit is set when the status refers to an 8800. Otherwise, it is reset. This allows for different meanings in the status field (and potentially other differences in the future, though none are defined at this time)

Reserved (Bit 23, mask 0x00800000)

This field is always set to zero.

Extended Point Status

The extended point status (PSX) data structure consists of a 16-bit word. This feature was added in PICS II.