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CEO: Dr. Bernt Götz • Phone +493641/66880 • Fax +493641/668866 • www.piezosystem.com
To synchronize the
NV200/D NET
PID controller loop execution to the SPI master the
spitrg
option
can be used. In mode
spitrg,0
the internal 20 kHz clock is used to trigger the digital control loop
interrupt. In mode
spitrg,1
the digital control loop interrupt is executed only when a new SPI
setpoint is received. This allows precise synchronization of several NV200/D NET controllers.
However, it is very important to make sure that SPI commands are sent with a 20 kHz update rate in
order to get the right timing for the digital filters, since they are parameterized with respect to a
constant sampling rate of 20 kHz.
8.5 Command list
All commands with one parameter to send are used in the following scheme:
<command>,<value>\r
Commands with indexing are used like this:
<command>,<index>,<value>\r
In case of read-only commands, commands without a value or to read back a value, the command is
issued without a value:
<command>\r
Command
Description
Value range
General Commands
s
Print full command list
-
reset
Hardware-reset of the controller
-
fenable
During controller power-up, cycle through the
entire piezo voltage range once
0= disabled
1= enabled
sinit
Initial actuator position after power-up
0
… 100 %
set
Setpoint as position or voltage
In open loop: voltage in V
In closed loop: position in µm or µrad
Range is limited by the actuators
stroke and voltage range
meas
For actuators with sensor: Position in actuator
units (µm or mrad)
For actuators without sensor: Piezo voltage in V
-
imeas
Measured piezo current
0 = piezo current 1
1 = piezo current 2
ctrlmode
Controller operation mode
0 = PID control
1 = ILC (identification mode)
2 = ILC (feedforward control mode)
3 = ILC (feedback control mode)
temp
Heat sink temperature
-
stat
Status register, see section 8.6 for details
-
posmin
Lower motion range limit
-
posmax
Upper motion range limit
-
avmin
Lower voltage range limit
-
avmax
Upper voltage range limit
-
