2 plus/minus signs and directions – Festo Электромотор MTR-DCI User Manual
Page 43
1. System overview
1-21
Festo P.BE-MTR-DCI-DN-EN en 1209a
Point of reference
Calculation rule
Axis zero point
AZ
= REF
+ a
Project zero point
PZ
= AZ
+ d
= (REF
+ a) + d
Lower software end posi-
tion
LSE
= AZ
+ b
= (REF
+ a) + b
Upper software end posi-
tion
USE
= AZ
+ c
= (REF
+ a) + c
Tab. 1/7: Calculation regulations for a dimensional reference system with incremental
measurement systems
1.6.2
Plus/minus signs and directions
All offsets and position values are vectors (with a given alge-
braic sign, + or -). The +/- operating direction of the vectors
can be assigned to the rotation direction of the motor shaft
(visual inspection of the motor shaft). The factory settings are
“+” for clockwise rotation and “-” for anticlockwise rotation.
The active direction can be reversed at the control panel (see
chapter 4.5.2) or via FCT. This can be useful when using
angular gear units or toothed belt drives. Homing must be
carried out again if the direction is reversed.
The direction in which the work load moves depends on the
gearing, the spindle type (left/right-rotating), the algebraic
signs on the positioning specifications (+/-), and the cur-
rently set active direction: