Schmalz SCPi FS RP, Operating Instructions Manual

Page: 34 / 58

Functions of the Vacuum Switch
34 / 58 EN-US · 30.30.01.01602 · 01 · 10/18
The detection of an external suction cycle is carried out using the adjustable limit values SPx and rPx that
indicate the limits for picking up and depositing a workpiece. The threshold for the maximum permissible
leakage is set using the parameter L-x in millibars per second. The following diagram shows the case of a
typical suction cycle where the system indicates a leakage and the vacuum generator drains many times:
Pressure p
[mbar]
Switching point SP
Reset point rP
Output
Suction cycle
begins
New
suction cycle
Suction cycle
ends
Time t
Peak recognition activates
leakage measurement
Low
leakage
Low
leakage
High
leakage
Another application for Condition monitoring mode occurs if the regulation threshold of the vacuum sys-
tem is never achieved and the vacuum generator permanently sucks. In this case, if the end vacuum is
20 mbar lower than the start vacuum, the switching point will also be activated.
For a very tight vacuum system where the second case shown always occurs in normal opera-
tion and indicates no error, Condition monitoring mode is not suitable.
8.3.5 Diagnostics Mode
Diagnostics mode monitors the internal warnings and error messages of the switch. When an error mes-
sage (error code in display or ISDU 130) or warning (CM bit in ISDI 146) appears, the switching point is ac-
tivated.
Diagnostics mode also includes the functions of Condition monitoring mode. That means the switching
point is also activated when the leakage measurement results in a warning.
8.4 Teach-in for Switching Points
A teach-in function is available to make it easier to set the limit values. This only affects one switching
point on one occasion and changes nothing on the selected switching point mode or switching point
logic.
ü To cancel a teach-in process, the required switching point must first be selected. This is done via IO-
Link, via ISDU 58 or in the menu item "
tCX
" in the basic menu.
4
In the menu, the teach-in starts immediately when the button is pressed; if it is done via IO-link,
the appropriate system command has to be written via ISDU 2 first.
ð The switch-on threshold SPX or FHx is set for teach-in in such a way that it is 20% below the actual
required measurement value. The reset threshold for vacuum values is set at 50 mbar below the
switch-on threshold. The associated hysteresis for window mode is set at 10 mbar for vacuum values.
ð After a successful teach-in process, an automatic display cycle of the newly set values appears in the
display.