The Cyclops may not work properly with a very long cable run. The maximum cable length depends on a number of factors such as:
- Supply voltage
- Cable resistance/capacitance
- Controller input sensitivity
Causes
There are a number of potential issues that are caused by long cables that may be happening.
Sensor Brown Out
The Cyclops operates off of a minimum of 5 V. Cables have a certain amount of resistance per foot, which will cause the supply voltage to drop. In some cases, the voltage that the Cyclops receives will be below the operational threshold. In some cases, operation may be erratic.
Signal Path Impedance
Cyclops operates as a dry contact. This means that the controller has a pull up resistor to power. When the Cyclops detects an arrival, it pulls the SIG connection down to ground (COM) through a 100 ohm impedance causing current to flow. This current through the pull up is detected by the processor on the controller. A long cable will add resistance to the circuit, which reduces the amount of current flowing through the circuit, which may be below the amount required by the controller.
Troubleshooting Tips
There are things that can contribute to these signal/power level issues. To help narrow it down, you can:
- Measure the supply voltage at the Cyclops PWR connection to make sure it is above 5 V
- Measure the voltage at the controller input
- Waiting for plunger: High Voltage (5 V on ALiEn2)
- Plunger arrives: Ground (0 V)