I/O Mode - selects the functionality of the input:

• Off - the input is ignored

• Digital - a weak pullup voltage is supplied by device on the GPI input, and the input is sampled at Sensor Read Intervals. If the voltage is pulled externally close to 0 V (or short-circuit to ground/GND), it will be classified as LOW (binary 0), and if it is above 0V (or open-circuit to ground/GND), it will be classified as HIGH (binary 1). It does not generate any alert messages.

• Low Level Trigger - a weak pullup voltage is supplied by device on the GPI input. A transition on the input from this pullup voltage to 0V (or short-circuit to ground/GND) will immediately transmit “input closed” alert message. Additionally, the input is sampled at Sensor Read Intervals, as in “Digital” mode.

• High Level Trigger - a weak pullup voltage is supplied by device on the GPI input. A transition on the input from 0V to this pullup voltage (or open-circuit to ground/GND) will immediately transmit “input opened” alert message. Additionally, the input is sampled at Sensor Read Intervals, as in “Digital” mode.

• Any Level Trigger - a weak pullup voltage is supplied by device on the GPI input. A transition on the input either from 0V to this pullup voltage (open-circuit to ground/GND) or from this pullup voltage to 0V (short-circuit to ground/GND) will immediately transmit “input opened” and “input closed” alert messages, respectively. Additionally, the input is sampled at Sensor Read Intervals, as in “Digital” mode.

• Pulse Counter - a weak pullup voltage is supplied by device on the GPI input. Any transition from this pullup voltage to 0V (a pulse) will be counted. The accumulated count will be transmitted and cleared at Transmit Intervals. This input has no debounce filtering for maximum count frequency, so the input should not have any glitches. This mode is meant for open-collector type of flow meters. 

• Pulse Counter (debounce) - the same behavior as Pulse Counter, but there is a debounce (ie. anti-glitch) filter. Maximum pulse frequency will be reduced, but input glitches will not be counted. This mode is useful when the sensor has slow changing pulses with glitches, such as mechanical switches or relays, such as tipping bucket rain sensors.

• Voltage - this mode measures input voltage level and is sampled at Sensor Read Intervals

• 4-20mA - this mode measures 4-20 mA current loop and is sampled at Sensor Read Intervals

• Resistance - this mode measures resistance of the input circuit and is sampled at Sensor Read Intervals

• Thermistor (1-Wire) - this mode measures ambient temperature with external 1-Wire sensor and is sampled at Sensor Read Intervals. (Note: only Zenseio approved thermistors are supported.)

Some I/O Modes have Threshold and Settling Time options.

Threshold Alert - when set to “On”, actively monitors input if it exceeds threshold values measured at Sensor Alert Check Intervals, as defined by start, stop, and step threshold values. 

When "Start Threshold Value" is greater than "Stop Threshold Value", low range will be monitored, that is, for example, when the temperature drops below "Start Threshold Value", an alert message will be sent. When "Start Threshold Value" is less than or equal to "Stop Threshold Value", a high range will be monitored, that is when the temperature goes above "Start Threshold Value", an alert message will be triggered. When the sensor values cross "Delta Step Values", alert messages will be triggered at each level, until the "Stop Threshold Value" level is reached. Once beyond "Stop Threshold Value", no more alerts will be triggered.

Note: the units of threshold values are the same as that of the expected input. For example, for voltage, the units are Volts, for current - they are mA, for temperature - they are degrees Fahrenheit.

Example of low range alerts: