This solution captures cycle counts on machines which are distributed around a factory floor. Voltage levels come from different PLC’s, and can be anywhere from 0 – 30V.
Design Goals:
- Work with any PLC vendor
- Remote capture of machine cycles
- Up to 30 machines
- Machine cycles of up to 250 / minute
- Wireless transmission of results
- Withstand temperatures of 110 degrees F.
- Wireless transmission distance indoors up to 300 meters.
The figure above shows a completed cycle counter. At top, is a 900Mz, high-gain antenna. Two LED’s (one red, one green) display the counter status. 5 Volts, 1.5ms power is provided to the bottom of the all-metal box. A cable brings the PLC signals into the counter. Both the power, and the PLC’s use locking connectors to prevent accidental disconnection.
Illustrated above is a finished counter, installed. The red LED lights when a cycle has been detected. Above the red LED, outside the box, is a high-gain 900 Mhz antenna that transmits the signals to a collector placed up to 300 meters away.
