Siemens SINUMERIK 802S Start-Up page 87

PLC interface signals when using a stepper motor in the controlled mode
When using a stepper motor as an axis (spindle), the PLC interface signals have to be used
as follows:
The "Servo enable" signal provided via the NC will not be used to turn off the drive ("Drive
Enable" is always active). This pertains to the following signals:
S
Servo Enable
S
Positioning measuring system ON/OFF
S
Parking
S
Error responses
It is the user's own responsibility to cause the PLC that the appropriate stepper motor drive is
brought to "Safe Stop" or is switched off.
Rotation monitoring of the stepper motor using BERO
Overview
A stepper motor will no longer follow the setpoint if the load torque becomes too large. The
rotation monitoring is intended to detect this faulty status.
At the moment when the BERO pulse occurs, the stepper motor setpoint position is compared
with the BERO actual position and, in case of error, the "Error: Rotation monitoring signal" is
created.
The rotation monitoring BERO must be overrun cyclically when the axes are traversed.
Usually, a cyclically occurring BERO is used both referencing and for rotation monitoring.
It is possible to switch the BERO for rotation monitoring in parallel to the BERO for referenc-
ing. It must, however, be made sure that the rotation monitoring is disabled when referencing
and that the rotation monitoring BERO does not provide a signal or the referencing BERO is
switched off when rotation monitoring is active.
Machine data
The MD 31100 BERO_CYCLE must contain the repetition cycle of the BERO in actual–value
increments. The MD 31110 BERO_EDGE_TOL will take into account any tolerances in the
BERO switching edge.
Activation
The speed monitoring is activated via the user interface signal 380x5000.0. It comes into ef-
fect for the appropriate axis only after referencing.
Error case
The error "Rotation monitoring" is signalled (interface signal 390x5000.0) and the monitoring is
switched off. The reference point is lost. To re–enable rotation monitoring, rereferencing is
required.
SINUMERIK 802S
6FC5 597–2AA00–0BP2 (01.02)
Start-Up
4.7 Commissioning
4-87