3. Instruction Set
3. Operand D occupies 8 consecutive word registers. The function of each device is as below:
D + 6 Converted DA value of Zenith 0 ~ 2000 Word
degree
D + 7
Converted DA value of Azimuth
0 ~ 2000 Word
degree
4. The execution time of SPA instruction costs up to 50ms, therefore we suggest users to execute
this instruction with an interval not less than 1 sec, preventing the instruction from taking too
much PLC operation time.
5. Definition of Zenith: 0° and 45°.
0° 45°
6. Definition of Azimuth:
N
0°
90°
180°
270
°
N
0°
90°
180°
270°
7. The correct time of the local longitude: If we suppose that it is AM8:00:00 in Taipei, and the
longitude is 121.55 degrees east, then the correct time of the local longitude in Taipei should
be AM8:06:12. Please refer to API168 DTM instruction (parameter k11) for more
explanation.