Programming
890CS Common Bus Supply - Frames B & D; 890CD Common Bus Drive and 890SD Standalone Drive - Frames B, C & D
Page
D-123
8
9
10
A
B
C
D
E
1
2
3
4
5
6
7
Parameter Descriptions
ENCODER FBK %
PREF: 158.08
Default: —.xx %
Range: —.xx %
This parameter shows the speed of the input encoder, as a percentage of the MAX SPEED parameter in the REFERENCE
function block.
SHAFT POSITION
PREF: 158.09
Default: —.xx deg
Range: —.xx deg
This diagnostic provides the motor shaft position (before the gear box).
* LOAD POSITION
PREF: 158.10
Default: —.xx deg
Range: —.xx deg
This diagnostic provides the motor load position (after the gear box).
* OUTPUT G'BOX IN
PREF: 158.05
Default: 1
Range: -2000000000 to
+2000000000
See OUTPUT G'BOX OUT below.
* OUTPUT G'BOX OUT
PREF: 158.26
Default: 1
Range: -2000000000 to
+2000000000
These two parameters define the gearbox ratio between the motor and the load. For example, if a 3:2 gearbox is fitted between
the motor and the load such that the motor turns through 3 revolutions for every 2 revolutions of the load, then set OUTPUT
G'BOX IN to 3, and set OUTPUT G'BOX OUT to 2. The software will then keep track of the load position.
If the power is removed and then reapplied, it is possible for the drive to keep track of the load position even if the shaft has
moved since the power was removed. This is only possible if the encoder is an absolute multi-turn. Otherwise, the load
position will be set equal to the motor position on power-up.
* The output gearbox functions LOAD POSITION, OUTPUT G’BOX IN and OUTPUT G’BOX OUT are intended to apply to
the feedback encoder, to allow the user to keep track of the speed and position of a load attached to the motor via a gearbox.
It will not normally be applicable to the reference encoder. However, the parameters are included here because it is possible
that the reference encoder may be derived from a motor with a gearbox. In this case it may be desirable to use the load
position as the reference. These parameters will make it possible to do this.