8
|
Functions
Baumer
30
Operating Manual
OM20/ OM30 RS485 with Modbus RTU | V1
8.3
Trigger mode
The
Trigger mode
function controls the acquisition of the measured values and thus also the
measurement frequency. The parameter settings offer you a choice between the
Free Running
and
Interval
trigger modes.
Free Running
trigger mode
n
The sensor measures constantly and at the highest possible measurement frequency.
n
The maximum measurement frequency varies depending on the characteristics of the mea-
surement object (or the exposure time). Example: Dark measurement objects (longer expo-
sure time) result in a lower measurement frequency than light-colored measurement ob-
jects.
n
The maximum measurement frequency is independent of the selected filter settings, since
measurement and processing of data proceed simultaneously.
n
Purpose/application: The
Free Running
trigger mode can be used in most applications (fac-
tory setting). The fastest possible recording of measurement results ensures a larger
amount of data.
Interval
trigger mode
n
The sensor measures with a constant time interval (adjustable in µs).
n
Observe the maximum possible measurement frequency in the
Interval
mode as well. If the
maximum possible measurement frequency is exceeded, the performance can worsen.
Therefore:
▪ Measure the maximum possible measurement frequency in the
Free Running
mode.
▪ Calculate the minimum time interval as follows:
min. time interval = 1/max. measurement frequency
n
Purpose/application: Use with dynamic applications (e.g. measurement objects on a con-
veyor belt) to detect all measurement objects.
Modbus RTU command – holding register:
Trigger
mode
Address 400 – Trigger Mode:
Address
Access
Number of
registers
Data type
Description
400 - 401
Read/write
2
int32_t
Select the trigger mode:
n
0: Free Running
n
2: Interval
Address 402 – Fix Time Trigger Intervall:
Address
Access
Number of
registers
Data type
Description
402 - 403
Read/write
2
uint32_t
Numerical time interval in
Interval
mode [µs]