the latched position. In software latching, a digital source – such as a digital input
of the drive control unit – is used for triggering, and the position value is received
from the actual position source of the axis, selectable by a parameter.
When a digital input of the FEN-xx module is being used for triggering, a low-pass
filter time can be applied by parameters 91.35 and 91.45 to counteract any noise
in the triggering signal.
Latch activation status is shown by 86.52.
It is possible to choose whether latching occurs only once (that is, the first time
the latching conditions are met) or continuously (every time the latching conditions
are met). See parameters 86.50 and 86.51 for the different configurations.
Settings and diagnostics
Parameter groups: 86.2 Actual position (page 463) and 91 Encoder module
settings (page 489).
Homing
Homing is started by activating the source selected by parameter 74.25. During
homing, bit 5 of parameter 74.1 is set and 74.10 indicates the status Homing.
During homing, the triggering parameters (86.50, 86.51 and 86.52) are used.
Existing latched values will be overwritten. After the homing finishes, bit 4 of 74.1
will be set.
In case a standard digital input is used as the homing switch source, set 86.33 to
Latch 1 SW input, then select the input in 86.56.
It is possible to use the same switch for homing that is configured as a hardware
limit switch (86.63 or 86.64). In this case, during homing, the switch will function
as a homing switch rather than a limit switch.
Homing must be completed to activate the software limits.
■
Homing modes
The diagrams below show the movement of the load with each homing mode.
InformationSymbol or abbreviation
Status of home switchDI
Normally-closedNC
Normally-openNO
Status of zero pulse received from encoderZ
Movement at homing velocity 1
Movement at homing velocity 2----------------
46 Position control program features