2 Inputs System Components Bleeding Resistor By default, if properly configured, the current should flow from the Input pin to the Input Common pin (when connected to a sourcing device), or from the Input Common pin to the Input pin (when connected to a sinking device). In some cases, the amount of current going through the sensing circuit is insufficient for the connected output device to match its minimum current requirement when the device is in an on or off-state, depending on the configuration of the circuit. To boost the flowing current, connect a 2.2 kOhm external bleeder resistor between the Input and Input Common pins. For example:
(Equivalent circuit only.) About the Connections in the Following Subsections The following subsections detail how to connect the most common third-party devices to the HAWK MV-4000 input signals. Note that HAWK MV-4000 input signals are optically isolated. Ground is only shown in the following subsections for reference, in case you need to reference your return path to ground. Power, as depicted in the following diagrams, represents a nominal voltage of 24 V (+/- 10%). For minimum and maximum voltage requirements, refer to the electrical specification of the optoisolated input signals, in the Electrical specifications subsection in Appendix C: General Specifications.
HAWK MV-4000 Smart Camera Guide 2-31