Position Control Monitor - Siemens SIMATIC S5 Manual

Technical Description of the IP 266
Note:
Software monitoring is possible only in the closed-loop control (automatic)
modes.
In the event of an "Error in the position control loop", the IP 266 aborts the job
currently in progress, using the specified maximum deceleration rate to do so. It
then resets the existing reference point, if any, and starts the open-loop control
"Follow-up" mode. The controller enable signal remains activated. You can now
modify and store machine data on the IP 266.
"Follow-up" mode is terminated as soon as the machine data has been stored,
and the IP is once again in closed-loop control mode.
2.7.2

Position Control Monitor

On the first automatic machining movement following IP 266 power-up, the
module checks the position control direction.
If signals A and B are reversed, the encoder changes the actual value in the
opposite direction to that specified by the setpoint. The IP attempts to match the
actual value to the setpoint over a period of ten IP cycles. During this time, the
analog voltage increases at a very rapid rate. If the two values are still progressing
in opposite directions after ten cycles, the current mode is revoked, the "Follow-
up" mode started, the controller enable (FUM) signal removed, and "Wrong
position control direction" output.
2-24
IP 266
EWA 4NEB 812 6057-02