4-20 mA — Configuration

Configuration Parameters

In addition to the GW4 configuration parameters the add-on has the following specific parameters:

Analog Channel Parameters

Key	Type	Default	Description
ch1Enable	Bool	true	Enable measurement on 4–20 mA input channel 1 (CH1)
ch1PreReadSec	Number	1	Wait time in seconds after powering CH1 before reading
ch1Samples	Number	200	Number of samples taken for one CH1 measurement
ch1Factor	Number	1	Scaling factor applied to the raw CH1 value
ch1Offset	Number	0	Offset added to the scaled CH1 value
ch1AlarmHigh	Number	[not set]	High alarm threshold for the CH1 measurement value
ch1AlarmLow	Number	[not set]	Low alarm threshold for the CH1 measurement value
ch2Enable	Bool	true	Enable measurement on 4–20 mA input channel 2 (CH2)
ch2PreReadSec	Number	1	Wait time in seconds after powering CH2 before reading
ch2Samples	Number	200	Number of samples taken for one CH2 measurement
ch2Factor	Number	1	Scaling factor applied to the raw CH2 value
ch2Offset	Number	0	Offset added to the scaled CH2 value
ch2AlarmHigh	Number	[not set]	High alarm threshold for the CH2 measurement value
ch2AlarmLow	Number	[not set]	Low alarm threshold for the CH2 measurement value
alarmCron	String	[not set]	Cron schedule used while an alarm is active
ch1PwrAfterBrownoutDur	Integer	0	Seconds to keep CH1 powered after first power-on or brownout

chXFactor and chXOffset Parameters

The measured raw value is multiplied by chXFactor and then chXOffset is added. All further calculations and alarm checks are done with this derived value.

chXAlarmLow and chXAlarmHigh Parameters

If the calculated measurement value is above chXAlarmHigh or below chXAlarmLow, an alarm is triggered. The number of triggered alarms and the time spent in the alarm state are measured and transmitted.

alarmCron

If an alarm is active, this cron is used instead of the regular cron. If empty, the regular sensor cron is used.