Komori lithrone 28 ultrasonic double sheet sensor trouble

Hi All
Having trouble setting up an ultrasonic double sheet sensor on a 4 colour Komori Lithrone 28.
Model UTSD-CK (1) Cosmotech

The bottom receiver remains undisturbed.

The top sender sensor mounting bracket broke and has been replaced.
I have lined the two up perfectly and there is an exact 25mm space between, as per the sensor manual specs.
There are 3 indicator LED's on the sensor control PCB.
The timing LED lights green correctly on rotation of machine.
The status LED lights orange when no sheet are detected, and turns green when a sheet is between the sensors.
But the "Alarm" LED does not light up at all. According to the manual, the LED should light green, with the "status" LED, when one sheet passes through and should light red when two or more sheets passes through.
Another technician in the past had tried setting it up and changed some of the settings on the PCB in the cabinet.
I have tried to set it correctly but the sensor manual does not indicate which settings do what or what the correct voltage readings should be on the various testing points on the PCB.
I am getting no joy in getting it to work properly and could really use some experienced advice.
Please can anyone assist?
Kind regards
Martin

 

Hi Sir:
do you have : 1) Schematic diagrams in PDF? 2) Sensor manual in PDF?
Maybe you can send me and help you.
However the Leds will be receive the same amount Voltage, look for bad contacts, or cold solder joint, and bad Resistance for Leds, or out of tolerance, or defective Led.
Let me know.

 

Hi, thanks for your reply Chock. I have schematic diagram for PCB of sensors. But it only indicates the input and output voltages of PCB. I can send to you when I get there again.
On the PCB is a few testing points to measure voltage. One for sender, one for receiver and one for signal. There is no indication of what these voltages should be and tbey all can change when potentiometer setting on PCB are changed.
Input and output voltages are 24vdc but I get different results when testing these points.
GND - SIG = 12.8V
GND - SND = 2.2V
GND - REC = 1.6V (no sheet)

There should be a reference to what is most ideal voltage on sender and receiving sensor when no sheet present and when one sheet present so that one can adjust the system optimally?
This is where I am stuck.

 

Hi Chock
I managed to sort out the sensor problems.
I emailed the sensor manufacturer in Japan and they sent me the electrical settings. I applied the correct settings and tuned the voltages correctly and it is working nicely.
Thanks for your assistance
Kind regards
Martin

 

Good idea Martian Congratulation.
Enjoy it.