Siemens SIMATIC S5 Manual page 281

IP 266
Select mode 3 (Controlled jog).
Select a low speed (approx. 1-5 %) via "Override".
Select the "Forward" function and observe the actual position; this value must
increase.
If the actual position value decreases, switch off the power section immediately!
In this case, you must interchange encoder signals A-A\ and B-B\ (if you are using
a 5 V encoder) or A* and B* (if you are using a 24 V encoder) and retest the
direction of rotation. Forward travel must result in an increase in the actual
position, reverse travel in a decrease.
Testing the hardware limit switches
Initiate forward traversing in mode 3.
Trip and hold the hardware end limit switch.
The traversing movement must be aborted with the "HW end limit switch
tripped" error message. There must be no further travel when a new "Mode 3
forward" command is issued.
Initiate reverse travel in mode 3.
Release the hardware end limit switch during traversing.
Trip the start limit switch.
The traversing movement must be aborted with the error message "HW start
limit switch tripped". There must be no further travel when a new "Mode 3
reverse" command is issued.
Start mode 3 "Forward" and release the hardware start limit switch during
traversing. Traversing movements in both directions are now once again
possible.
EWA 4NEB 812 6057-02
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