58
SMT-BD2/m
CHAPTER 9 – Appendix
CHAPTER 9 - APPENDIX
1 - USE OF THE LIMIT SWITCHES & "CVO" INPUTS
During the amplifier operation, the enabling of the
FC
+
limit switch stops any motor displacement in the positive
direction and the enabling of the
FC-
limit switch stops any motor displacement in the negative direction. The
motor is decelerating with the amplifier
Maximum current
value in order to get the shortest possible braking time.
2 - USE OF THE "AMP. READY" & "POWER READY" OUTPUTS
When an amplifier fault is released, the
AMP. READY
output is immediatly disabled (contact is open). After
elimination of the error source, the amplifier can be reset via pins 12 and 13 of the X4 connector.
If the position initialization reference must be kept when a stored fault is released on the amplifier and the power
supply turned off, it is necessary to have an auxiliary supply for the logic board which is independent from the
power supply. In this case, the
JK
and
KL
jumpers of the logic board allow to inhibit or to release the "Undervolt."
fault when the amplifier is turned on.
JK
jumper closed and
KL
jumper open configuration :
If the auxiliary supply is turned on before the main power supply, the "Undervolt." fault is displayed and
can hide a fault of lower priority. The
AMP READY
and
POWER READY
outputs are both inactive
(contact is open) until the power supply in on.
JK
jumper open and
KL
jumper closed configuration :
The "Undervolt." fault is inhibited when turning on the auxiliary supply before switching on the main
power supply. The
AMP READY
output is then active and
POWER READY
remains inactive (contact
open) until the main power supply is on.
3 - FOLLOWING ERROR PROTECTION
The positioner following error detection is operating as described below.
The measured position error is continuously compared with the theoretical position error given by the position loop
model. When the difference exceeds the
following error threshold
value, the position following error is released.
This following error detection scheme allows to adjust the
following error threshold
to a minimum value when a
very sensitive following error detection is required for safety reasons.
When the position following error is released, the amplifier speed reference value is set at zero and the motor is
braking in the shortest time according to the available amplifier current. The amplifier is then disabled as soon as
the zero speed is reached. However, if the motor braking distance exceeds the
maximum braking distance
parameter value during the braking operation, the amplifier is immediately disabled. This braking distance
monitoring function allows to protect the operator and the machine against uncontrolled motor movements that
could be generated by a drive failure. If the
maximum braking distance
parameter value is set at zero, when the
position following error is released, the amplifier is immediately disabled and the motor freewelling.
Positive and negative directions depend on the encoder and motor wirings. So, before mounting and
wiring the limit switches, it is recommended to find the positive and negative directions of the motor.
!
Position loop model
Following
error
threshold
Position
reference
Measured
position error
Theoretical
position error
Comparator
Position following
error
-
+
Absolute
value
