ITU_G2 Data Points

Introduction

The ITU_G2 can measure a number of different inputs and parameters associated with these inputs. To report all these parameters when they are mostly unused would be a waste of space in the log record. Therefore the ITU_G2 includes a log map to specify which parameters are to be logged. The use of a log map also allows the flexibility to select data points to be logged from external sensors.

To make it easier to remember which parameter is which the ITU_G2 groups the parameters into a set of logical devices. Logical devices are identified by a letter and then the data values associated with this logical device are identified by a number. Some logical devices are internal to the ITU_G2 and are therefore always present whereas others are external devices that may or may not be connected. For example the analog inputs are an internal logical device since they are part of the ITU_G2 but the temperature sensor needs to be connected so is an external logical device.

In addition to the logical devices of the ITU_G2, external physical devices may also be included in the log map. These devices are identified by numbers and include SDI-12 sensors and wireless remotes.

Available Data Points

Logical device	Data Point(s)	Description	Units
A	1-8	Analog inputs 1-8	V^[1]
A	9	12V battery voltage	V
B	1	Battery fuel gauge accumulated current	Ah
	2	Battery fuel gauge average current	A
	3	Battery fuel gauge temperature	°C
C	0	Wind speed input count (i.e. wind run)
C	1-8	Digital inputs 1-8 counts
D	1	Digital inputs current state (bits 0-7 = inputs 1-8)
D	2	Relay and virtual relay states (bits 0-3 = relays 1-4)
F	1-8	Digital input frequencies	Hz
H	1-2	Humidity reading from temperature/humidity sensor	%RH
J	1	HTP sensor humidity	%RH
	2	HTP sensor temperature	°C
	3	HTP sensor pressure	Pa
T	1-8	Temperature sensors	°C
W	1	Wind direction average since last log	°
	2	Wind speed average since last log	Hz
	3	Wind speed peak gust since last log	Hz
	4	Wind count (wind run) since last log
Z	1	Time in SPE, semi-bitfield, format
	2	Time in Unix time format
	3	Real time clock temperature reading	°C

1. When an analog input is configured as a voltage input then the units of the reported value are in volts. However, if an input is configured as 4-20mA then the reported value is a unitless fraction of the sensor full scale range. That is, a current of 4mA is reported as 0 and and current of 20mA is reported as 1. To obtain the reading of the senor in its measurement units one should multiply the reported value by the sensor's full scale range. Error values or less than 4mA will be reported as negative values.