Rockwell Automation 873P Ultrasonic Sensors with Dual Discrete/Single Analog Outputs Installation - Manual (Page 2)

Rockwell Automation 873P-IN004A-EN-P—October 2014
2 873P Ultrasonic Sensors with Dual Discrete/Single Analog Outputs
One Set Point Function
In this sensing mode, a set point is taught in the defined sensing
range. The working range of the sensor becomes the minimum
sensing distance to a user-taught set point. Depending on where
the set point is taught, the output will turn ON when the target
passes between the minimum sensing distance of the sensor and
the taught set point. The analog output is scaled between those
two set points. When using the one set point mode it is only
possible to configure the sensor for normally open logic and
rising ramp analog output. It is not possible to configure the
sensor for N.C. or falling ramp.
Set Point 1 (P1):
1. Place the target at the desired set point.
2. With the target still in place, press the teach button then
release.
The yellow and green LEDs flash simultaneously, indicating that
the first set point P1 is now set. The sensor is waiting for the P2 set
point.
Set Point 2 (P2):
Keep the target in the same position you used to set P1.
1. The yellow and green LEDs flash simultaneously. Press the
teach button, then release.
The yellow LED blinks twice, indicating that the sensor is ready for
use. The minimum sensing distance is indicated on page 1 in the
Specifications table.
When configuring the sensor for one set point
mode it is very important that the target is at the
exact same distance for both the first and second
push of the teach button. If the target (or sensor)
has moved even slightly, the detected ranges will
be different for the two pushes of the teach
button, and the sensor will be configured for
Window Mode.
The green and yellow LEDs flash asynchronously
for about two seconds indicating there is no
target present within the sensing range of the
sensor and, therefore, no set point to teach.
When this happens, the 873P ignores this teach
attempt and restores its previous settings. By
comparison, when an object is detected during
the teach, the yellow and green LEDs flash
synchronously and continue flashing until the
second push of the teach button.
20 mA
N.O.
Pin 4
(BK)
Blind Z
one
4 mA
mm P1=P2 Minimum
Sensing
Distance BZ
H
Pin 2
(WH)
L
H
L
IMPORTANT
IMPORTANT
LED Indicators: Dual PNP Discrete Output and
One Analog Output
1
1
The analog output depends on the user-taught set points for the dual discrete sensor.
Therefore, it does not have a separate status LED.
2 Green LED indicates that an echo is reflected back to the sensor by an object, not
necessarily the target. Primary use is alignment.
3 For single discrete sensors, LED A triggers ON/OFF depending on target position
relative to the taught set point(s) and if N.O. or N.C. logic is used. In the case of a dual
discrete sensor, LEDs A and B trigger ON/OFF depending on the target position relative
to the taught set points and on the logic used (N.O. or N.C.).
Other Functions
Lockout Feature for Teach Button
The lockout feature locks the push button to prevent unwanted
teaching of the sensor.
Lock Teach Button: Press the teach button for eight seconds,
until the yellow LEDs A and B flash alternately with the green LED
C. Release the teach button. The push button is now locked.
Unlock Teach Button: Press the teach button for eight seconds,
until the yellow LEDs A and B flash alternately with the green LED
C. Release the teach button. It is once again possible to teach the
sensor.
Double PNP Output LED Functions
LED Color Function
A Yellow P1 Point in double digital output
B Yellow
P2 Point in double digital output/Teach
function
C Green ECHO LED/Teach function
Operating Mode
Green LED
(Alignment)
Yellow LED A
(Output) Yellow LED B (Teach)
Standard Operation
Target Present ON 2
ON/OFF
3
ON/OFF
3
Target Absent ON/OFF 2 ON/OFF 3 ON/OFF 3
TEACH
BUTTON
YELLOW LED B
Teach Function
YELLOW LED A
Output State
GREEN LED C
A B
C
M30 LEDs
Echo LED/Teach Function