Instruction Manual PSE2xxC
25
f) Drag error
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 (SDO
#2005), 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.
g) 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. There are two ways of generating an automatic run abort
in a case like this: node guarding und heartbeat consumer.
In the first case (node guarding), guard time and life time factors must be
programmed into the drive. The master then must cyclically transmit the heartbeat to
the drive as a remote object.
In the second case (heartbeat consumer), node ID and cycle time of the master
heartbeat must be sent to the device as consumer heartbeat. The master must then
cyclically transmit this heartbeat.
The second option generates less bus load, because the master needs only to
transmit an unconfirmed master heartbeat (only one message for all consumers).
h) Jog run mode
With the help of the jog run bit
s in the control word (bit 8 for “jog run to larger values”
an
d bit 9 for “jog run to smaller values”) a manual run can be performed, provided that
bit 4 (release) is inactive. The release of positioning runs and manual runs (control
word bit 4) and the control word bits for jog runs (bits 8 and 9) cannot be set
simultaneously. Changing the control word bits while running (for example from
positioning run to jog run) aborts a run in the other operation mode.
The step width for a short activation time of a jog run bit can be set via SDO #2022.
Such a single step is being executed if one of the jog run bits is being activated. If the
jog run bit is being deasserted before the end of the single step, it will be completed
nevertheless. If the same jog run bit stays active further on, after a short waiting time
a continuous manual run might join the single step under some circumstances. This
continuous manual run will run as long as the jog run bit stays activated. For this,
additionnally to the activation of the jog run bit
also bit 3 (‘release for manual run in
jog run mode
’) has to be activated. If bit 3 is not set, each activation of a jog run bit
results in a single step, even if the jog run bit is activated longer than the duration of
the single step.
The idle period before the drive switches into manual run is specified with SDO
#2023. In manual run the drive runs maximum to the specified limit switch position
(SDO #2016 resp. #2017).
If during an jog run both jog run bits are being activated, the run is aborted
immediately. A new jog run is only possible if both jog run bits are deasserted.
i) Reference runs
The PSE2xxC positioning system is equipped with an absolute or partially absolute
measuring system
, therefore there’s no need for a reference run when powering on
