Rockwell Automation 57C422B 2 Axis Servo Module - Manual (Page 68)

4-40 2-Axis Servo Module M/N 57C422B
the application software interrogates it.
4.43 Register 81: Velocity Error
Register 81 contains the velocity error. Velocity error is the
difference between the internally commanded velocity and
the current velocity. Register 81 is 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. Command (R66, b11) is issued. The units are
encoder counts/scan.
4.44 Register 82: Digital Input Status
Register 82 contains the digital input status. The values
reported in register 82 are the actual values of the inputs
without regard to the status of any bits contained in register
2. Refer to figure 4.43.
Figure 4.41 – Following Error Register
Figure 4.42 – Velocity Error Register
Figure 4.43 – Digital Input Status Register