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 166 / 240
Phone +49 721 4846-0, Fax +49 721 4846-1019, Email
The default value of the
FieldbusAxis Resolution
parameter is 0.0001 which results in the following
scaling of position values:
Min. value
EtherCAT master
Min. value E-727
with axis unit µm
Min. value E-727
with axis unit µrad
Min. value E-727
with axis unit mrad
1
0.0001 µm = 0.1 nm
0.0001 µrad = 0.1 nrad
0.0001 mrad = 0.1 µrad
You can change the scaling to make optimum use of the position resolution of the E-727. In order
to change the scaling, adapt both the
FieldbusAxis Resolution
parameter of the E-727 and scaling
factor numerator of the EtherCAT master.
You can read or adjust the
FieldbusAxis Resolution
parameter value via the TCP/IP or USB interface
only; for details, see “Parameters” (p. 185). Parameter changes must be done in the nonvolatile
memory and require a reboot of the E-727 to become effective in the EtherCAT bus.
The conversion between values of the EtherCAT master and E-727 (EtherCAT slave) is as follows:
SlaveTargetValue = MasterTargetValue * FieldbusAxisResolution
MasterCurrentValue = SlaveCurrentValue / FieldbusAxisResolution
Changing the scaling also changes the value of the position range limit (object 0x607B) of the axis.
EtherCAT Communication
Communication State Machine
The states of the connection to the EtherCAT network are described by a communication state
machine. The communication state machine is independent of the drive state machines which are
described on p. 169.
Figure 38: EtherCAT communication state machine