Installation manual

Publication 1747-RM001G-EN-P - November 2008
Application Specific Instructions 7-17
Read High-speed Clock
Instruction (RHC)
The Read High-speed Clock Instruction (RHC) provides a high performance
timestamp for performance diagnostics and performing calculations such as
velocity.
Enter Parameters
Destination - The address to store the current value of the 10 µs free running
clock. It can be an integer address (Nx:x) or Float address (Fx:x). The integer
address supports 16 bits range time (0 to 655.36 ms). The float address gives
the exact time for the free running clock value with 20 bits range time (0 to
10.48575 seconds).
Compute Time Difference
Instruction (TDF)
The compute Time Difference Instruction (TDF) is used to calculate the
number of 10 µs ticks between any two time-stamps captured using the RHC
instruction. This lets your program determine the time difference between any
two events using a 10 µs timebase.
Enter Parameters
This instruction has three parameters. All of these parameters should be of the
same data type (Nx:x or Fx:x).
• Start - The address of the earliest value previously captured using the
RHC instruction.
• Stop - The address of a later value captured using the RHC instruction.
• Destination - The address to store the result of the time difference
calculation.
RHC
Read High Speed Clock
Dest N7:0
RHC
Fixed SLC
5/01
SLC
5/02
SLC
5/03
SLC
5/04
SLC
5/05
•••
TDF
Compute Time Difference
Start N7:72
Stop N7:73
Dest N7:74
TDF
Fixed SLC
5/01
SLC
5/02
SLC
5/03
SLC
5/04
SLC
5/05
•••