Description ODSL 30
Leuze electronic GmbH + Co. KG
ODSL 30
22
Behavior of the switching outputs of the ODSL 30/D…
In addition, the ODSL 30/D… with serial output also has two switching outputs. The position within the
measurement range at which the switching outputs become active can be set arbitrarily via a teach line or
via configuration. In addition to the switching points, it is also possible to configure the switching hysteresis,
the switching behavior (light/dark switching), and the type of switching output (PNP high active or NPN low
active or PNP/NPN push-pull).
Teaching always takes place towards the upper switching point (see figure 3.6 on page 16). The lower
switching point is set to the value '199' by default and can be adjusted via the operating menu. The
following table applies for a lower switching point of 199mm.
Notes regarding the termination of the data lines of the ODSL 30/D 485…
The ODSL 30/D 485… features a combined transmitter and receiver component that can transmit serial
data according to the RS 485 and RS 422 standard (see TIA/EIA-485-A or DIN66259, Part 3).
These standards define some basic rules that should be followed in order to achieve the most reliable data
transmission:
• The data lines A and B (which correspond to the ODSL 30 pins Tx+ and Tx-) are connected to a
characteristic impedance of Z
0
≈
120
Ω
via a 2-wire twisted pair cable.
• The end of the data line (and the beginning in case of RS 485) is terminated using a 120
Ω
resistor.
The ODSL 30/D 485… does not have an internal bus termination.
• The RS 485 bus participants are wired in an linear bus topology, i.e., the data line is fed from one
bus participant to the next. Stub cables are to be avoided or to be kept as short as possible.
• The RS 485 specification assumes an inactive potential difference of U
AB
≥
200mV between the data
lines. A bus termination in the form of a voltage divider should be implemented in order to maintain
this level. Usually, it is connected to the RS 485 coupling module of the PLC.
The RS 485 specification permits transmission rates in the megabit range for up to 32 participants. The
ODSL 30/D 485… is designed for a data rate of typically 9600 baud (600 … 115200 baud can be config
-
ured). In practice, this means that the strict requirements regarding the bus termination and the cabling are
"softened" for a few bus participants.
However, it is important to maintain the bus idle levels (U
AB
≥
200mV). If the PLC coupling module does
not include a bus termination with voltage divider, the following circuit may be used.
4
0x10
Always = 0 (reserved)
3
0x08
Always = 0 (reserved)
2
0x04
1 = sensor deactivated, 0 = sensor activated
1
0x02
1 = no signal or signal too low, 0 = signal OK
0 (LSB)
0x01
1 = laser defective, 0 = laser OK
Bit number
Value
Meaning
Object distance
Light switching
Dark switching
Output Q1
Output Q2
Output Q1
Output Q2
No object (no signal)
Off
Off
On
On
< 200mm
1)
On
On
Off
Off
< teach value
On
On
Off
Off
> teach value
Off
Off
On
On
1) Only if a reception signal is available that can still be evaluated, otherwise same as "no object"
