Siemens SIMATIC FM 452, Руководство пользователя, Страница: 101 / 210

Settings
9-3
FM 452 Electronic Cam Controller
C79000-G7076-C452-04
9.2 Set Actual Value / Set Actual Value on-the-fly / Cancel Set
Actual Value
Definition
With the settings “Set actual value/Set actual value on-the-fly”, you assign a new
coordinate to the current encoder reading. The coordinate system is shifted as a
result by the value: ACT
new
– ACT
current
•
ACT
new
is the specified value
•
ACT
current
is the actual value at the time of execution.
Calculating the New Coordinates
All the positions you specify in the modified coordinate system can be calculated
according to the following formula:
coordinate
new
= coordinate
old
+ (ACT
new
- ACT
current
)
Requirements
•
The axis must be synchronized.
•
With “set actual value on-the-fly”: Digital input I1 must be connected.
Sequence of the Setting
1. Enter the coordinate for the actual value or for the flying actual value in the
channel DB.
– Linear axis:
You must select an actual value so that the software limit switch is still within
the range of movement after the setting has been read.
The value of the offset resulting from (ACT
new
- ACT
current
) must be less
than or equal to the value of the permitted travel range (maximum 100 m or
1000 m).
– Rotary axis:
The following rule must apply to the specified actual value:
0
≤
actual value < end of rotary axis
2. Set the appropriate trigger bits in the channel DB.
3. Call FC CAM_CTRL.
“Set actual values” is executed immediately.
“Set actual value on-the-fly” is executed at the next rising edge at digital input
I1. The FVAL_DONE bit is set.