NORD Drivesystems BU0210 - Manual (Page 14)

SK 2x5E with "PosiCon Functionality"
14 Subject to technical amendments BU 0210 GB
With the aid of a value which can be parameterised in parameter P609 [01] "Offset Position" the zero point can
be set to a different position to that which is determined by the reference point. The offset is applied after
conversion of the encoder rotations to motor rotations. After changes to the speed ratio/reduction ratio P607
[01] and P608 [01] the offset position value must be entered again.
3.2.1.1 Reference point run via digital inputs or BUS I/O In bits
The Reference point run is started via one of the digital inputs or one of the Bus IO In bits. For this a digital input
must be programmed for the appropriate function (P420[01]...[04] "Function Digital Input", setting 22).
For the Bus IO In Bits the corresponding Bit / Array (P480 "Bus IO In Bits", setting 22) must be parameterised.
The direction of the reference point search is specified via the signals "Enable Left/Right". The current setpoint
frequency determines the speed of the reference point run. Via one of the 4 digital inputs the reference point
is also read in. For this a digital input must be programmed for the appropriate function (P420[01]...[04]
"Function Digital Input", setting 23). For the Bus IO In Bits the corresponding Bit / Array (P480 "Bus IO In Bits",
setting 23) must be parameterised.
In order to also realise the function "Reference Point Run" via a serial interface or via the Bus IO In bits, one of
the "Bus Setpoint Values" (P546[01]...[03]) must be set to the setting "Bus IO In Bits 0...7" and under P480
"Function Bus I/O IN Bits" the function setting 22 must be assigned to the corresponding bit.
Sequence of the reference point run: With the reference point run enabled, the drive unit moves in the direction
of its setpoint value (Enable Right/Left, +/- Setpoint). On reaching the reference point switch, the signal at the
digital input or Bus IO In Bit "Reference Point" reverses the direction of travel. Therefore the drive unit moves
away from the reference switch again. After the switch has been left, the reference point run is complete. If the
drive unit is already at the switch at the start of the reference point run, the reference point run is immediately
started with the inverse direction of rotation. After leaving the switch the reference point run is complete and
the current position is set to 0 or to the value set in parameter P609 "Offset Position". The drive unit remains at
the new zero point until the reference point run is stopped by the removal of the signal. In the setpoint mode
P610 "Position Increment Array" = 1 (relative positioning) the setpoint position is simultaneously set to 0. With
appropriate parameterisation of one of the parameters "Digital Output Function" (P434, setting 20 - reference
point), the frequency inverter reports the end of the reference point run with corresponding adoption of the
reference point. The feedback for the end of the reference point run can also be reported via the Bus IO OUT
bits (P481, "Bus IO Out Bits", setting 20).
If an incremental encoder without the function "Save Position" is used (See P604 "Encoder Type") the actual
position in parameter P601 "Current Position" is set to "0" when the frequency inverter is switched on. For
parameterisation with the function "Save Position" the last saved value is taken as the actual position.
The output message "Reference Point" shows that a valid reference point is available. The outputs are
switched off when a reference point run is started and are switched on again after the completion of the
reference point run.
If the option "Save Position" (P604 "Encoder Type") is not selected (factory setting) the relay or the output are
switched off when the inverter is switched on.
If the option "Save Position" is selected the relay or the output are switched on immediately after the inverter is
switched on. Control via one of the Bus IO Out Bits is accordingly identical.