NIS-TR Temperature Sensor (RTD)

RTD Temperature Sensor

General information

MSxxx Overview

Mechanics

• Dimensions 60 x 95 x 85mm (109mm including fixing brackets)
• 96mm spacing between brackets
• IP 65
• Solid ABS & PC material

RTD Temperature sensor properties

• Handles 100Ω to 1kΩ (at 0°C) Platinum RTDs (PT100 to PT1000)

• 2-wires, 3-wire or 4-wire connection

• 15-Bit ADC Resolution; Nominal Temperature Resolution 0.03125°C (Varies Due to RTD Nonlinearity)

• Total Accuracy Over All Operating Conditions: 0.5°C (0.05% of Full Scale) max

• ±45V Input Protection

• Fault Detection (Open RTD Element, RTD Shorted to Out-of-Range Voltage, or Short Across RTD Element)

• Direct fifth-order linearization for best accuracy

Wiring

Probe settings

number of wires	jumpers configuration	Probe connection
4 wires	JP2 jumper on 1-2	FORCE+ IN+ IN- FORCE-
	JP3 NC
	JP4 NC
3 wires	JP2 jumper on 2-3	FORCE+ IN+ IN-
	JP3 NC
	JP4 jumper ON
2 wires	JP2 jumper on 1-2	IN+ IN-
	JP3 jumper ON
	JP4 jumper ON

Magnetic Switch Protocol description

MSxxx Generic Magnetic Switch Protocol

Radio frames description

MSxxx Generic Application Protocol

Uplink data Frame format

The uplink payload contains multiple fields: <mask>: bit field on 1 byte indicating the presence of other fields. Bit 7 is always to 1 because the mask is never extended on next byte.

bit 0 : indicates the presence of <nb_meas> field.

bit 1 : indicates the presence of <rtd_temp> field.

bit 2 : indicates the presence of <voltage> field.

bit 3 : indicates the presence of <internal_temp> field.

bit 4 : is reserved.

bit 5 : indicates the presence of <cause> field.

When bit 0 is not set, it means that other fields are present only once (nb_meas = 1).

if (mask.bit0 == 1) :

   <nb_meas>: 1 byte containing the number of measures which follow.

if (mask.bit1 == 1) :

   <rtd_temp>: 2*<nb_meas> bytes containing the measured temperatures in 0.1 °C. Each temperature is a signed integer on 16 bits in big endian [-32768..+32767].

if (mask.bit2 == 1) :

   <voltage>: 2*<nb_meas> bytes containing the voltages measured by the sensor in millivolts. Each voltage is an unsigned integer on 16 bits in big endian.

if (mask.bit3 == 1)

  <internal_temp>: 1*<nb_meas> bytes containing the measured internal temperatures (using MCU internal sensor). Each temperature is a signed integer on 8 bits in big endian in °C [-128..+127].

if (mask.bit5 == 1) :

   <cause>: 1 byte containing the cause of the uplink frame. It is a bit field:
       Bit 0 indicates a periodic measure
       Bit 1 indicates the high threshold exceeding (temperature > high threshold)
       Bit 2 indicates the high hysteresis exceeding (temperature < high threshold - high hysteresis)
       Bit 3 indicates the low threshold exceeding (temperature < low threshold)
       Bit 4 indicates the low hysteresis exceeding (temperature > low threshold + low hysteresis)
       Bit 5 indicates the measure has been forced manually (with magnetic switch)
   Usually <cause> field is absent when threshold detections are disabled (periodic measures only)

Thus the uplink frame format is <mask><nb_meas><rtd_temp1>...<rtd_tempN><voltage1>...<voltageN><internal_temp1>...<internal_tempN><cause>

Default <mask> value is 0x83 which means that the default frame is <mask><nb_meas><rtd_temp1>...<rtd_tempN>

Some examples (in hexadecimal):

   “820119”: the frame indicates one temperature of +28.1 °C.
   “8302FFCB000C”: the frame indicates two temperatures of -5.3 °c and +1.2 °C.

Downlink Frame format

The sensor configuration contains the following fields:

   <up_frame_mask>: the mask identifying the different fields present in uplink frames (possible values are described in “Uplink data Frame format” section)
   <nb_meas_for_tx>: the number of measures required to trigger a transmission (possible values are [1..8]
   <meas_period>: the period of the measures in <perdiod_unit> seconds(possible values are [600..65535]
   <period_unit>: the unit of <meas_period> in seconds, the resulting period is <meas_perios>*<period_unit> seconds
   <mode>: bit field enabling/disabling the measures (threshold detections and periodic measures)
   <subperiod>: subdivision of period for threshold detection, actual measurement period is (<meas_period>*<period_unit>)/<subperiod>
   <high_threshold>: value of high threshold
   <high_hysteresis>: value of high hysteresis
   <low_threshold>: value of low threshold
   <low_hysteresis>: value of low hysteresis
   <sensor_type>: identifies the type of sensor (PT100/PT1000 and 2/3/4 wires)

It is possible to change the sensor configuration using the Nemeus downlink protocol. The downlink frame must be sent on the MS008 LoRaWAN port (10).

The downlink frame has the following format:

<cmd>: 1 byte containing WRITE_CFG_CMD=0x02

<mask>: bit field on 1 byte indicating the presence of other fields. Most significant bit (bit7) is always to 1 because the mask is never extended on next byte.

Bit0 indicates the presence of <up_frame_mask> field

Bit1 indicates the presence of <nb_meas_for_tx> field

Bit2 indicates the presence of <meas_period> and <period_unit> fields

Bit3 indicates the presence of <mode> and <subperiod> fields

Bit4 indicates the presence of <high_threshold> and <high_hysteresis> fields

Bit5 indicates the presence of <low_threshold> and <low_hysteresis> fields

Bit6 indicates the presence of <sensor_type> field

If (mask.bit0 == 1):

   <up_frame_mask>: 1 byte containing the uplink frame mask

If (mask.bit1 == 1):

   <nb_meas_for_tx>: 1 byte containing the number of measures required to trigger a transmission

If (mask.bit2 == 1):

   <meas_period>: 2 bytes in little endian (LSB first) containing the period of measures in <period_unit> seconds
   <period_unit>: 1 byte containing the unit of <meas_period> in seconds (default value is 1 second)

If (mask.bit3 == 1):

   <mode>: 1 byte encoded as follows:
       bit0: enable(1)/disable(0) high threshold detection
       bit1: enable(1)/disable(0) high hysteresis detection (when leaving high level state)
       bit2: enable(1)/disable(0) low threshold detection
       bit3: enable(1)/disable(0) low hysteresis detection (when leaving low level state)
       bit4: enable(1)/disable(0) periodic measurements
       bit5 to bit7: reserved
   <subperiod>: 2 bytes in little endian containing the period subdivision

If (mask.bit4 == 1):

   <high_threshold>: signed integer on 2 bytes in little endian containing the high threshold in 0.1 °C [-2000..+8000]
   <high_hysteresis>: unsigned integer on 1 byte containing the hysteresis when leaving high threshold state in 0.1 °C [0..255]

If (mask.bit5 == 1):

   <low_threshold>: signed integer on 2 bytes in little endian containing the low threshold in 0.1 °C [-2000..+8000]
   <low_hysteresis>: unsigned integer on 1 byte containing the hysteresis when leaving low threshold state in 0.1 °C [0..255]

If (mask.bit6 == 1):

   <sensor_type>: unsigned integer on 1 byte containing the sensor type [11..16]
       11: PT100 2 wires
       12: PT100 3 wires
       13: PT100 4 wires
       14: PT1000 2 wires
       15: PT1000 3 wires
       16: PT1000 4 wires

Thus the downlink frame format is <cmd><mask><up_frame_mask><nb_meas_for_tx><meas_period><period_unit><mode><subperiod><high_threshold><high_hysteresis><low_threshold> <low_hysteresis><sensor_type>.

Some examples in hexadecimal:

   “028181”: set the <up_frame_mask> to 0x81 => the next uplink frames will include the <usonic_dist> field only (no <voltage> field and no <temp> field)
   “028E04605401”: set <nb_meas_for_tx> to 4, <meas_period> to 21600*<period_unit> seconds and <period_unit> to 1 second => one measure every 6 hours and one transmission every 4 measures (every day). Each uplink frame will include 4 measures

Power consumption

Please find below a tool to calculate power consumption vs number of measures and transmissions.