Use a discrete 24 VDC input for the part-detection signal; a 0–10 V analog input is not required for counting on/off events. The proposed design uses a three-wire PNP photoelectric sensor, with the sensing distance reduced from the original 200 mm maximum to 180 mm for the proposed IFM O8T202. Before wiring, verify the exact Millenium 3 model’s input type and electrical limits because the supplied evidence does not identify the controller variant.
Choose the Sensor and Input Type
| Design item | Selection | Engineering constraint |
|---|---|---|
| Controller signal | Discrete input | The counter needs one state transition per passing part, not a proportional 0–10 V signal. |
| Supply | 24 VDC | Confirm that the sensor and selected Millenium 3 input share compatible voltage levels. |
| Sensor principle | Photoelectric | The parts are aluminum and the required sensing distance was initially up to 200 mm. |
| Output arrangement | PNP, three-wire | Use only if the exact controller input accepts a sourcing sensor signal. |
| Proposed sensor | IFM O8T202 | The proposed installation reduces the sensor-to-part distance to 180 mm. |
PNP identifies the output polarity, but it does not by itself prove compatibility. Confirm the sensor output circuit, controller input circuit, input voltage range, input current, common-terminal arrangement, and off-state behavior in the two product documents.
Wire the Detection Signal
Power the three-wire sensor from the 24 VDC supply, connect its reference conductor to the supply reference, and connect its switched PNP output conductor to the selected discrete input. Connect the Millenium 3 input common exactly as required by the documentation for the chosen hardware model. Do not treat a serial-output sensor as a discrete sensor; a serial data stream cannot directly provide the counter’s required on/off input event.
- Record the exact Millenium 3 model and verify that its selected input supports a 24 VDC PNP signal.
- Confirm the O8T202 conductor functions from its documentation before terminating any wire.
- Connect the sensor supply, reference, and switched output according to both wiring diagrams.
- Monitor the input while passing one part at a time. Verify one input transition per part before enabling the counter or pneumatic motion.
Configure and Verify the Count
Connect the discrete input condition to the counter block and set the output condition for 100 detected parts. The intended sequence is: each valid sensor transition increments the counter once; when the accumulated count reaches 100, the programmed output condition requests cylinder operation.
Validate the installation with a controlled batch. Compare the physical part total with the controller count and confirm that one part does not create multiple increments or no increment. The evidence does not define counter reset behavior, output duration, cylinder valve wiring, or motion interlocks; define and test those functions before operating the industrial machine.
Resolve Compatibility Before Commissioning
If the input never changes, verify sensor power, sensing alignment, common wiring, and whether the input is compatible with a PNP sourcing output. If the count is inaccurate, observe the discrete input during individual drops and correct the sensor position or detection conditions until each part produces exactly one usable event. Do not replace this event signal with a 0–10 V measurement unless the application is redesigned around an analog value.
FAQ
Does a Crouzet Millenium 3 counter need a 0–10 V input?
No. This application requires a discrete input transition for each detected part; the counter output is configured to operate when the count reaches 100.
Can a three-wire PNP photoelectric sensor connect directly to a Millenium 3?
Only if the exact Millenium 3 input accepts a 24 VDC PNP sourcing signal. Verify the input circuit, common connection, voltage limits, and sensor conductor functions in both product documents before wiring.
How do I verify that the parts counter will count accurately?
Monitor the discrete input and pass parts individually at the proposed 180 mm sensing distance. Confirm exactly one input event and one counter increment per part, then verify that the output condition occurs at 100 parts.
