User Manual
E727T0005, valid for E-727
BRO, 2019-06-28
Physik Instrumente (PI) GmbH & Co. KG, Auf der Roemerstrasse 1, 76228 Karlsruhe, Germany
Page 145 / 240
Phone +49 721 4846-0, Fax +49 721 4846-1019, Email
Configuration Parameters
For the axes of the E-727, the usage of data segment 1 of the SPI interface can be configured via
parameters:
Usage of the data received from the host
Limits for position scaling
See "Parameters" beginning on p. 185) for more information on the parameters and their handling.
Configuring the Usage of Received Data
For the individual axes of the E-727, the
FastIF Axis Input Usage
parameter (ID 0x10000500)
determines the usage of the data received from the host via data segment 1 of the SPI interface.
The value of the
FastIF Axis Input Usage
parameter can be as follows:
0 = The data received from the host is ignored for the axis.
1 (default) = The data received from the host is used as target value for the axis (closed-loop or open-loop,
depending on the servo mode).
2 = The data received from the host is used as current axis position. If this option is selected, the E-727
ignores the current axis position provided by the sensor channels via the input matrix (p. 29).
Configuring the Limits for Position Scaling
Note that position scaling is
not
necessary when the 32-bit floating point data type is set via the
FastIF Data Type
parameter (ID 0x10000501). In this case, the data can be read and written
directly in axis units. Scaling is only necessary if any integer data type is set. Using the
Used Range
for Fast IF
parameter (ID 0x10000506), you can select which limits are to be used for scaling the
data sent via data segment 1 of the SPI interface:
0 = Fast IF data limits (parameters 0x10000502 and 0x10000503)
1 = Range limits of stage (parameters 0x07000000 and 0x07000001; provided by the ID-chip of the stage)
By default, the parameter is set to 1, i.e. the range limits of the stage are used for all axes.
Closed-Loop Operation
In closed-loop operation, the
FastIFUsedLowLimit
and
FastIFUsedHighLimit
parameters
(0x10000504, 0x10000505) give the currently used limits for the data sent via data segment 1 of
the SPI interface. Depending on the setting of
Used Range for Fast IF
(0x10000506), the currently
used limits are identical to the range limits of the stage or to the Fast IF data limits.
Open-Loop Operation
In open-loop operation, it is necessary to extend data input range to cover the whole travel range.
The limits for the input data sent via data segment 1 are calculated from the
FastIFUsedLowLimit
,
FastIFUsedHighLimit
and
FastIFOpenLoopLimitExtend
parameters as follows:
FastIFOpenLoopLowLimit = FastIFUsedLowLimit - (FastIFUsedHighLimit - FastIFUsedLowLimit) *
FastIFOpenLoopLimitExtend
FastIFOpenLoopHighLimit = FastIFUsedHighLimit + (FastIFUsedHighLimit - FastIFUsedLowLimit) *
FastIFOpenLoopLimitExtend
FastIFOpenLoopLimitExtend
must be
≥
0. Normally 0.1 should be sufficient, providing 10% reserve
in both directions.