9
05.01
9.7 Circuit examples =1 to =10 with SIMODRIVE 611 analog
9-277
Siemens AG 2001 All rights reserved
SIMODRIVE 611 Planning Guide (PJU) – 05.01 Edition
Circuit example =7 “External speed monitoring,
spindle drive”
Application
Several type C standards demand safe speed monitoring for the functions:
S Standstill monitoring for a spindle drive to release a protective door
S Speed monitoring functions for max. speeds or velocities in the setting–up
mode, e.g. 50 min
–1
or in the automatic mode, depending on the chuck size
or the clamped workpiece as a result of the maximum permissible clamping
and centrifugal forces. The max. limit is set, e.g. using a selector switch
which can be locked.
The speed is automatically monitored for zero speed when the automatic mode
is cancelled or when the protective door is opened. The setting–up speed (crawl
speed) is enabled with the enable signal. After the enable signal has been with-
drawn, the speed is again monitored for standstill after a delay. The speed sen-
sing for the monitoring device e.g. be either realized using an incremental enco-
der or two proximity switches mounted onto the spindle. The device to provide
the speed monitoring can be purchased from various manufacturers which is
the reason that it is only shown in principle without any precise connection de-
signations. The user must incorporate the device used into his control, taking
into account the safety–related requirements and the manufacturers data.
Note
The monitoring function of the device should be proven using an acceptance
test and documented !
Functions
Standstill monitoring
The speed monitoring device is actively switched in via the control voltage. Con-
tact –A11/terminals 77–78 at the monitoring unit is closed, via the safe standstill
signal of the spindle drive and the door release is released in circuit =6. There-
fore, the time until the protective door has been released can be significantly
shortened with respect to the delayed release using contactor =4–K33 MSD
Stop. In this case, contact =4–K33/81–82 must be jumpered in circuit =6. For
NC machining programs with low spindle speeds, the time for the drive to brake
down to standstill is appropriately short so that it is not necessary to wait for the
delay, set at contactor =4–K33, for the max. braking time until the door is ope-
ned. The interlocking circuit, terminals 701–702, changeover, stop drives t1 s
for external standstill monitoring functions MSD should be inserted in front of
contactor =4–K32/A1. In this case, after the spindle drive has issued a safe
standstill signal, the drives are already shut down after t1 s and go into safe
standstill.
9 Important Circuit Information
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