ACS Tech80 SB1391 User Manual

HARDWARE INTERFACE PARAMETERS 7-13
SB1391 Hardware and Setup Guide - Document revision no. 1.14
7.5.4.2. Monitoring Velocity Profile
The output voltage as a function of the actual velocity (AV) in counts/seconds is:
MF
out
AV
D
V 2
512
000,20
22
10 ×
×
×=
The velocity scale factor depends on the value of D22. Internally, the maximum velocity value is
represented by the value 1638.
For example, if D22 was set according to a maximum velocity of 1,000,000 counts/second, then
when the actual velocity is 1,000,000 counts/second, the internal (integer part of the) velocity
value is 1638. When the actual velocity is 500,000 counts/second, the internal velocity value is
819.
To monitor the velocity, set MN to 1. MF must be set to a value that will prevent overflow of the
output. In the above example if the actual velocity is getting close to 1,000,000 counts/second
(internal velocity of 1638), set MF to -2. If the actual velocity is less than 500,000 counts/second
(internal velocity of 819) set MF to -1. If the actual velocity is 100,000 counts/second (internal
velocity of 163), set MF to 1. This will provide a better dynamic range for the monitored signal.
7.5.4.3. Monitoring Position Error
Monitoring the position error is useful for improving the tracking quality, for finding the source of
torque disturbances, for measuring settling time and for setting the acceleration feed forward
(AF).
To monitor the position error, reset MN to 3 and DC to 4. Usually the error value is less than 500,
so MF should be set to a non-negative value.
TABLE 7-8 Scale factor as a function of MF
MF VPE [volts/count]
-2 0.00488
-1 0.00976
0 0.0195
1 0.039
2 0.078
3 0.156
4 0.312
7.5.4.4. Monitoring Current Position
Monitoring the current position (CP) is a useful tool for measuring settling time. Usually the
value of CP is large. While moving, the monitor signal will overflow. Ignore it. Just examine the
last part, where the axis settles.
The [volts/counts] scale factor is identical to the scale factor for position error monitoring.
Example: Set the system to check whether the axis overshoots the target point by more than 10
counts when moving in MM1 between CP=0 and CP=32768.
Solution: Set DC to 2, MN to 3 and MF to 3. A 10 count overflow will generate a 1.5V overshoot
at the end of the move.

ACS Tech80 SB1391 Specifications

General

Brand	ACS Tech80
Model	SB1391
Category	Controller
Language	English