Determine The Exposure Time Via The Plc - Primes FocusParameterMonitor FPM 60 Original Instructions Manual

Measurement settings
11.5

Determine the exposure time via the PLC

Several consecutive measurements are usually required to determine the exposure time.
Before each additional laser pulse (before each measurement), check the remaining capacity of the absorber.
The value of the remaining capacity is sent via the PLC.
NOTICE
Damage/destruction of the device due to excess temperature
If the remaining energy input is not taken into account before each measurement, the absorber
can be damaged or destroyed.
 Check the remaining capacity (variable "FPM result: remaining_capacity") and the absorber temperature
("FPM result: absorber temperature) before triggering a measurement process (in the case of caustic
measurements before each individual plane measurement).
 Also note any overtemperature warnings from the device (flag „FPM status: too hot" is set)
Example:
With a laser power of 2 kW and an exposure time of 200 ms, the energy of 400 J is absorbed.
E = P · t = 2000 W · 0,2 s = 400 J
The FPM is designed for measuring short-term exposure and has no automated exposure time adjustment.
The appropriate exposure time must therefore be determined for the various beam configurations.
The combination of the parameters and measurement results transferred via the fieldbus offers the opportunity
to do this.
The setting based on the transmitted results should be shown and explained here.
No settings are required for the power measurement apart from making the device ready to measure. Only
the parameters relevant for setting the exposure time are taken into account. The remaining settings are not
changed during the process and are set as follows:
Adress Parameter
268 Trigger level
264 Trigger delay
270 Attenuation
276 Beam position z
260 BeamFindCounts
262 BeamFindPercent
280 Resolution X
282 Resolution Y
284 Window size x
286 Window size y
288 Window position x
288 Window position y
Revision 06 EN 02/2023
Value Comment
2000 Fixed value for pulse detection [cts].
0 Delayed start of measurement [µs]
0 [dB]; not used here
0 Only for documentation [µm]
200
Settings for beam search
30
512
Maximum resolution
512
2240
Maximum asymmetric measurement window (Attention:
device specific), values are noted on the device.
1493
0
Offset for centering the measuring window on the
camera chip
0
55