Siemens SINUMERIK 840D sl Programming Manual page 195

Note
The feed must be adjusted to suit the measuring task in hand.
In the case of MEASA and MEAWA, the correctness of results can be guaranteed only at feed
rates with which no more than one trigger event of the same type and no more than four
trigger events occur in each position controller cycle.
In the case of continuous measurement with MEAC, the ratio between the interpolation cycle
and position control cycle must not exceed 8 : 1.
Trigger events
A trigger event comprises the number of the probe and the trigger criterion (rising or falling
edge) of the measuring signal.
Up to four trigger events of the addressed probe can be processed for each measurement,
i.e., up to two probes with two measuring signal edges each. The processing sequence and
the maximum number of trigger events depend on the selected mode.
Note
The same trigger event is only permitted to be programmed once in a measuring job (only
applies to mode 1)!
Operating mode
The first digit in the mode setting selects the desired measuring system. If only one
measuring system is installed, but a second programmed, the installed system is
automatically selected.
With the second digit, i.e., the measurement mode, the measuring process is adapted to the
capabilities of the connected control system:
• Mode 1: Trigger events are evaluated in the chronological sequence in which they occur.
• Mode 2: Trigger events are evaluated in the programmed sequence.
• Mode 3: Trigger events are evaluated in the programmed sequence, however no
Job planning
Programming Manual, 03/2006 Edition, 6FC5398-2BP10-1BA0
5.8 Extended measuring function (MEASA, MEAWA, MEAC) (option)
When this mode is selected, only one trigger event can be programmed for six-axis
modules. If more than one trigger event is specified, the mode selection is switched
automatically to mode 2 (without message).
monitoring of trigger event 1 at START.
Note
No more than two trigger events can be programmed if two measuring systems are in
use.
Special Motion Commands
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