Specifications

Operation

See "Control Value Generation" in the E-517 User Manual for details.

Switching between ONLINE and OFFLINE mode can be done by:

■ Channel-specific ONL commands sent over the communications

interface or received from a macro running on the E-517

■ Pressing the trackball on the E-517 front panel when the main screen

is displayed; switches the mode for all channels at once

The current control mode is visible for the individual channels on the main

screen of the E-517 display, see

"Display Screens" (p. 21). Using the ONL?

command, you can check the current control mode on a per-channel basis.

NOTES

Upon power-on or reboot, all piezo channels of the system are by

default in OFFLINE mode. You can switch them to ONLINE mode

using a start-up macro, see "Start-Up Macro" (p. 40) for details.

In OFFLINE mode, the E-517 accepts all commands just as in ONLINE

mode. The only difference between the modes is the control source

selection of the channel.

In ONLINE mode the SERVO switches of all channels must be set to

OFF on the piezo control electronics.

3.2.2 Servo Mode (ON / OFF)

The current servo mode determines if a motion axis is driven in open-loop

(servo OFF) or closed-loop (servo ON) operation:

■ Closed-loop operation:

Any control input (analog, DC offset, E-517 input like move

commands, trackball settings and wave generator output) is

interpreted as target position. Based on this target position and on

the position feedback of the corresponding sensor channel, a servo

loop generates the control value for the piezo channel. The servo

loop thus maintains the axis position. It is not located in the E-517 but

in the analog part of the piezo control electronics (see the

corresponding User Manuals of your system for more information).

The servo loop applies a proportional-integral (P-I) servo-controller, a

notch filter and a slew rate limiter. The slew rate can also be

influenced by the E-517 (parameter ID 0x07000200).

■ Open-loop operation:

Any control input is interpreted as piezo voltage target. Open-loop