Siemens SINAMICS S120, Function Manual

Page: 182 / 1094

Servo control
4.20 Central probe evaluation
Drive functions
182
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
4.20 Central probe evaluation
Frequently, motion control systems have to detect and save the positions of drive axes at an
instant in time defined by an external event. For example, this external event may be the
signal edge of a probe. The following can be necessary:
● Several probes have to be evaluated
● The actual position values of several axes must be saved with a probe event.
For the central probe evaluation, the instant in time of the probe signal is detected and saved
by a central function. From the sampling values of the position signals of the various axes,
the control interpolates the times of the actual position values at the probe instant. Three
evaluation procedures are implemented in SINAMICS S120 for this purpose.
The evaluation procedures can be set using parameter p0684:
● With handshake (p0684 = 0)
Factory setting
● Without handshake, 2 edges (p0684 = 1)
A change to p0684 = 0 or 1 is possible in the RUN state.
● Without handshake, more than 2 edges (p0684 = 16)
Measuring several signal edges per probe, without handshake:
A change to p0684 = 16 only becomes active after "Save parameters" and "POWER ON".
A change of p0684 = 16 to p0684 = 0 or 1 only becomes active "After save parameters"
and "POWER ON".
The fail safety of the standard PROFIdrive connection without handshake cannot be
guaranteed. The "Without handshake" function has been released for "integrated" platforms
(e.g. SINAMICS integrated in SIMOTION D425). You must use the "With handshake"
function to ensure absolute reliability when detecting the probe.
PROFIdrive telegrams for the central measuring function
● Telegram 390: No probe
● Telegram 391: 2 probes (when p0684=0/1)
● Telegram 392: 6 probes (when p0684=0/1)
● Telegram 393: 8 probes (when p0684=0/1)
● Telegram 394: No probe
● Telegram 395: 16 probes, time stamp (p0684 = 16)