UTC-Time-Quality BYTE format specification
The TwinCAT UTC-Time-Quality components are coded in BYTE in the following way:
Bit | Component | Type | Value range | Description |
|---|---|---|---|---|
0 | LeapSecondsKnown | BIT | 0..1 | Quality of the leap second (0:=unknown, 1:=known). |
1 | ClockFailure | BIT | 0..1 | Quality of the timer (0:=good, 1:=erroneous). |
2 | ClockNotSynchronized | BIT | 0..1 | Quality of the time synchronization (0:=synchronized, 1:=not synchronized). |
3 | Accuracy0 | BIT | 0..1 (MSB) | Accuracy of the time information (precision of the fraction of a second). Max. number of significant bits in the T_UtcTime.fractionOfSecond component. |
4 | Accuracy1 | BIT | 0..1 | |
5 | Accuracy2 | BIT | 0..1 | |
6 | Accuracy3 | BIT | 0..1 | |
7 | Accuracy4 | BIT | 0..1 (LSB) |
Coding of the precision in the UTC-Time.Quality.Accuracy0..4 bits.
Precision | Accuracy0 | Accuracy1 | Accuracy2 | Accuracy3 | Accuracy4 | E_UtcTimeAccuracy |
|---|---|---|---|---|---|---|
0-bit | 0 | 0 | 0 | 0 | 0 | Zero |
1-bit | 0 | 0 | 0 | 0 | 1 | _01 |
2-bit | 0 | 0 | 0 | 1 | 0 | _02 |
3-bit | 0 | 0 | 0 | 1 | 1 | _03 |
4-bit | 0 | 0 | 1 | 0 | 0 | _04 |
5-bit | 0 | 0 | 1 | 0 | 1 | _05 |
6-bit | 0 | 0 | 1 | 1 | 0 | _06 |
7-bit | 0 | 0 | 1 | 1 | 1 | _07 |
8-bit | 0 | 1 | 0 | 0 | 0 | _08 |
9-bit | 0 | 1 | 0 | 0 | 1 | _09 |
10-bit | 0 | 1 | 0 | 1 | 0 | _10 |
11-bit | 0 | 1 | 0 | 1 | 1 | _11 |
12-bit | 0 | 1 | 1 | 0 | 0 | _12 |
13-bit | 0 | 1 | 1 | 0 | 1 | _13 |
14-bit | 0 | 1 | 1 | 1 | 0 | _14 |
15-bit | 0 | 1 | 1 | 1 | 1 | _15 |
16-bit | 1 | 0 | 0 | 0 | 0 | _16 |
17-bit | 1 | 0 | 0 | 0 | 1 | _17 |
18-bit | 1 | 0 | 0 | 1 | 0 | _18 |
19-bit | 1 | 0 | 0 | 1 | 1 | _19 |
20-bit | 1 | 0 | 1 | 0 | 0 | _20 |
21-bit | 1 | 0 | 1 | 0 | 1 | _21 |
22-bit | 1 | 0 | 1 | 1 | 0 | _22 |
23-bit | 1 | 0 | 1 | 1 | 1 | _23 |
24-bit | 1 | 1 | 0 | 0 | 0 | _24 |
Impermissible | 1 | 1 | n | n | n | _25_invalid.._30_invalid |
Not specified | 1 | 1 | 1 | 1 | 1 | Unspecified |
Samples
The table below contains some BYTE numerical values and the values after conversion to the formatted UTC Time-Quality string and the structured type: T_UtcTimeQuality.
BYTE | STRING(9) | T_UtcTimeQuality | Description |
|---|---|---|---|
2#00000000 | 'UQ#000|0' | STRUCT(0) | All components have the value: 0. Precision: 0-bit. |
2#11000000 | 'UQ#000|3' | STRUCT(Accuracy3:=1, Accuracy4:=1) | Precision: 3-bit. All other components have the value 0. |
2#10100100 | 'UQ#001|5' | STRUCT(ClockNotSynchronized:=1, Accuracy2:=1, Accuracy4:=1) | Timer is not synchronized. |
2#11111010 | 'UQ#010|31' | STRUCT(ClockFailure:=1, Accuracy0:=1, Accuracy1:=1, Accuracy2:=1, Accuracy3:=1, Accuracy4:=1) | Timer signals an error. Precision: Not specified. All other components have the value 0. |