Instruction Manual PSx3xxPN
31
3.8
Drag error monitoring
During a positioning run, the device compares the computed target position with the
current actual value. If the difference is larger than the “drag error” value (Par. 46),
the device sets the corresponding bit in the status word. This situation is especially
likely to occur if external factors (required torque, voltage to motor too low) prevent
the device from achieving the target rpm.
By setting Par. 46 to 0 the drag error monitoring can be disabled.
3.9
Drag error correction
With Par. 48 the drag error correction can be enabled. With this feature enabled, the
drive will raise or lower the target speed proportional to the drag error by the
configured value. The drive attempts under consideration of the configured maximum
current to compensate the drag error which has developped by controlling the target
speed to a value which lays slightly above or below the specified value of the target
speed (Par. 53).
By setting Par. 48 to 0 the drag error correction can be disabled.
Drag error monitoring and correction take effect always except during a braking
operation when approaching a target position or when aborting a positioning. The
actual target speed when accelerating is determined by the actual speed at the
beginning of the positioning and the acceleration setting (Par. 58).
3.10 Abort run when the master fails
If the connection to the master is interrupted during a positioning run, the master
cannot abort an actual run. In order to generate an automatic run abort in this case,
there’s a mechanism implemented in the drive that monitors the communication to the
IO controller. In case of a timeout, the drive will abort any positioning (if bits 1-0 of
Par. 93 are set to 01, which is the default value). If the connection contains valid data
after its re-establishment, the drive might continue to move immediately (where
applicable).
3.11 Devices with optional holding brake
The device models PSx30xPN-14, PSx31xPN-14, PSx32xPN and PSx33xPN can be
supplied with an optional holding brake. This brake prevents the output shaft from
turning when the power supply to the motor is removed, or, if the motor holding torque
is too low, to a maximum of the level of the nominal torque. A small degree of rotation
always occurs at the output, i.e. the brake cannot be used to hold the drive at a
defined position (for this purpose where appropriate the holding torque might be
increased with the help of Par. 65 and Par. 66).
To release the brake when a run command is transmitted, these devices first wait for
a short time and then run a few increments against the actual direction of movement.
The brake is closing at the end of every run (by default 1 sec after the end of the run,
Par. 75). The advantage of this feature is, that in case of many subsequent runs the
brake has not to be released anew each time.
Содержание PS*3**EIP series
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