Rockwell Automation 57C422B 2 Axis Servo Module - Manual (Page 67)

PROGRAMMING 4-39
4.40 Registers 76, 77: Current Gearing
Position
Registers 76, 77 contain the current gearing position.
Registers 76, 77 are only updated when the "latch status"
command in register 66 is issued. This ensures that data will
be consistent while the application software interrogates it.
The units are encoder counts. This data always originates
from the hardware gearing inputs on the given axis,
regardless of the selections made in register 65, bit 9, and
register 38, bits 0 and 1.
4.41 Registers 78, 79: Current Velocity
Registers 78, 79 contain the current velocity i.e., the number
of counts in the period defined in R83. Registers 78, 79 are
only updated when the "latch status" command in register 66
is issued. This ensures that the data will be consistent while
the application software interrogates it. The units are
encoder counts.
4.42 Register 80: Following Error
Register 80 contains the following error. Following error is
the difference between the internally commanded position
and the "current feedback position" in R74, 75. Register 80 is
only updated when the "latch status" command in register 66
is issued. This ensures that the data will be consistent while
Figure 4.39 – Current Gearing Position Registers
Figure 4.40 – Current Velocity Registers