Programmer's Guide
ObjectC 100
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http://csa.cedes.com/ 19
l
min
= (T5-T2)
x
v
l
max
= (T6-T1)
x
v
l
min
Minimum length
l
max
Maximum length
T1 Last measurement before detecting object G1
T2 First measurement after detecting G1
T5 Last measurement while detecting G1
T6 First measurement G1 is no longer detected
v Speed
(constant)
2.3.9.
Period duration
The duration of the period for periodic mode (2.3.8) determines parameter 75 [4B Hex]. It is calculated
accordingly:
t
p
= n
x
13.1 [ms] + t
m
t
p
Period duration [ms]
n
Multiplier according to parameter 75 (3.. 255)
t
m
Measurement time 0 ... 25 ms (see chapter 4.6)
The measurement time t
m
has to be added as
tolerance. Its calculation is documented in chapter
4.6. It is dependant on the light curtain length and,
with a light curtain of 250 elements, amounts to 25
ms.
2.3.10.
Single/Periodic evaluation
The periodic mode (chapter 2.3.8) can be specified as a single or a periodic evaluation.
Table 43: Parameter for single/periodic evaluation
Parameter
Value
Event measuring
0
Single
Min/Max 1) of the actual (last) measurement
83 [53 Hex]
Single/Periodic evaluation
1
Periodic
Min/Max 1) of the last period
1) Min/Max refers to telegram 65 [41 Hex] and 67 [43 Hex]
When single evaluation is selected, the controller sends the minimum and maximum values of the actual
measurement every periodic time point (e.g. T1 in Figure 5) with telegram 65 [41 Hex] and 67 [43 Hex]. Minimum
refers to the lowest interrupted beam number and maximum refers to the highest interrupted beam. In this case,
objects that are too small or that arrive in the detection area too quickly, i.e. during an interval, are not detected
(see Figure 5, goods G1 and G3 not detected).
With the periodic evaluation, the minimum and maximum values refer to the entire passing period, i.e. T1 to T2,
T2 to T3 etc. This means, the lowest and highest interrupted beams during this period. In this mode the goods G1
and G3 of Figure 5 are recognized.
Figure 5: Goods which fall in a time interval due to smaller size or travelling too quickly
will only be recognized in the periodic evaluation of periodic mode.
2.3.11.
X-Y Measurement with zones
With a cascading Object100 light curtain system, a X-Y measurement can be performed. Using commands 64
[40 Hex] and 66 [42 Hex] the lowest and highest interrupted beams can be requested. According to configuration,
the response telegrams 65 [41 Hex] and 67 [43 Hex] can also be sent spontaneously (see chapter 2.3.6 - 2.3.10).
The parameters 79 [4F Hex] and 80 [50 Hex] allow the definition of up to 32 zones per axis. The condition of
each zone can be seen in the response telegrams 65 [41 Hex] and 67 [43 Hex]. It is important to note that the Y-
axis is always the light curtain closest to the controller, irrespective of whether it is vertical or horizontal. It is
strongly recommended that the y-axis section of the light curtain is set up vertically to avoid confusion with
results.
