Direktronik Ltc2 User manual

LTC2 - LoRaWAN Temperature Transmitter User

Manual

last modiﬁed by Xiaoling

on 2023/02/02 14:47

User Manual for LoRaWAN End Nodes - LTC2 - LoRaWAN Temperature Transmitter User Manual

Table of Contents

1. Introduction ........................................................................................................................................................................ 6

1.1 What is LTC2 LoRaWAN Temperature Transmitter ................................................................................................ 6

1.2 Features ........................................................................................................................................................................ 6

1.3 Applications ................................................................................................................................................................... 7

1.4 Hardware Change log ................................................................................................................................................... 7

1.5 Pin Deﬁnitions and Switch .......................................................................................................................................... 7

1.5.1 Jumper JP2 ( Power ON) ..................................................................................................................................... 7

1.5.2 LED .......................................................................................................................................................................... 7

1.5.3 PT100 Interfaces .................................................................................................................................................... 7

1.5.4 Reset Button ........................................................................................................................................................... 7

1.6 Probe Variant ............................................................................................................................................................. 7

2. How to use LTC2? ........................................................................................................................................................... 9

2.1 Connect to PT100 sensors ......................................................................................................................................... 9

2.2 How it works? ............................................................................................................................................................ 9

2.3 Quick guide to connect to LoRaWAN server (OTAA) ............................................................................................. 9

2.4 Uplink Payload ............................................................................................................................................................ 16

2.5 Datalog Feature ......................................................................................................................................................... 17

2.5.1 Unix TimeStamp .................................................................................................................................................. 17

2.5.2 Set Device Time ................................................................................................................................................... 18

2.5.3 Poll sensor value .................................................................................................................................................. 18

2.5.4 Datalog Uplink payload ....................................................................................................................................... 19

2.6 Alarm Mode ................................................................................................................................................................. 21

3. Conﬁgure LTC2 via AT Command or LoRaWAN Downlink ...................................................................................... 21

3.1 Set Transmit Interval Time ....................................................................................................................................... 21

3.2 Enable PT100 channels ............................................................................................................................................ 22

3.3 Set External Sensor Mode ........................................................................................................................................ 22

3.4 Quit AT Command ..................................................................................................................................................... 23

3.5 Set system time .......................................................................................................................................................... 23

3.6 Set Time Sync Mode ................................................................................................................................................. 23

3.7 Set Time Sync Interval .............................................................................................................................................. 23

3.8 Retrieve data .............................................................................................................................................................. 24

3.9 Enable Alarm mode ................................................................................................................................................... 24

3.10 Alarm check time ..................................................................................................................................................... 24

3.11 Set Alarm Threshold ................................................................................................................................................ 24

3.12 Set Calibrate Value .................................................................................................................................................. 25

3.13 Poll Calibrate Value ................................................................................................................................................. 25

3.14 Print data entries base on page ............................................................................................................................. 25

3.15 Print last few data entries ....................................................................................................................................... 26

3.16 Clear Flash Record .................................................................................................................................................. 27

4. Battery & How to replace .............................................................................................................................................. 27

4.1 Battery Type ............................................................................................................................................................... 27

4.2 Replace Battery .......................................................................................................................................................... 28

4.3 Power Consumption Analyze ................................................................................................................................... 28

5. Firmware Change Log and Upload Firmware ............................................................................................................. 29

 ............................................................................................................................................................................................... 29

6. FAQ .................................................................................................................................................................................. 29

6.1 How to use AT Command to conﬁgure LTC2 ........................................................................................................ 29

6.2 How to connect a customized PT100 cable? ........................................................................................................ 30

6.3 What is the frequency range of LTC2 LoRa part? ................................................................................................ 33

6.4 How to change the LoRa Frequency Bands/Region ............................................................................................. 34

7. Trouble Shooting ............................................................................................................................................................ 34

7.1 AT Command input doesn't work ............................................................................................................................ 34

8. Order Info ........................................................................................................................................................................ 34

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User Manual for LoRaWAN End Nodes - LTC2 - LoRaWAN Temperature Transmitter User Manual

9. Packing Info ..................................................................................................................................................................... 34

10. Support ........................................................................................................................................................................... 35

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User Manual for LoRaWAN End Nodes - LTC2 - LoRaWAN Temperature Transmitter User Manual

Table of Contents:

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User Manual for LoRaWAN End Nodes - LTC2 - LoRaWAN Temperature Transmitter User Manual

•1. Introduction

•1.1 What is LTC2 LoRaWAN Temperature Transmitter

•1.2 Features

•1.3 Applications

•1.4 Hardware Change log

•1.5 Pin Deﬁnitions and Switch

•1.5.1 Jumper JP2 ( Power ON)

•1.5.2 LED

•1.5.3 PT100 Interfaces

•1.5.4 Reset Button

•1.6 Probe Variant

•2. How to use LTC2?

•2.1 Connect to PT100 sensors

•2.2 How it works?

•2.3 Quick guide to connect to LoRaWAN server (OTAA)

•2.3.1 Step 1: Create a device in TTN with the OTAA keys from LTC2

•2.3.2 Step 2: Power on LTC2

•2.4 Uplink Payload

•BAT

•Status & EXT

•Channel1 data and Channel 2 data

•Unix TimeStamp

•2.5 Datalog Feature

•2.5.1 Unix TimeStamp

•2.5.2 Set Device Time

•2.5.3 Poll sensor value

•2.5.4 Datalog Uplink payload

•2.6 Alarm Mode

•3. Conﬁgure LTC2 via AT Command or LoRaWAN Downlink

•3.1 Set Transmit Interval Time

•3.2 Enable PT100 channels

•3.3 Set External Sensor Mode

•3.4 Quit AT Command

•3.5 Set system time

•3.6 Set Time Sync Mode

•3.7 Set Time Sync Interval

•3.8 Retrieve data

•3.9 Enable Alarm mode

•3.10 Alarm check time

•3.11 Set Alarm Threshold

•3.12 Set Calibrate Value

•3.13 Poll Calibrate Value

•3.14 Print data entries base on page

•3.15 Print last few data entries

•3.16 Clear Flash Record

•4. Battery & How to replace

•4.1 Battery Type

•4.2 Replace Battery

•4.3 Power Consumption Analyze

•5. Firmware Change Log and Upload Firmware

•

•6. FAQ

•6.1 How to use AT Command to conﬁgure LTC2

•6.2 How to connect a customized PT100 cable?

•6.3 What is the frequency range of LTC2 LoRa part?

•6.4 How to change the LoRa Frequency Bands/Region

•7. Trouble Shooting

•7.1 AT Command input doesn't work

•8. Order Info

•9. Packing Info

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User Manual for LoRaWAN End Nodes - LTC2 - LoRaWAN Temperature Transmitter User Manual

•10. Support

1. Introduction

1.1 What is LTC2 LoRaWAN Temperature Transmitter



The Dragino LTC2 Industrial LoRaWAN Temperature Transmitter is designed to monitor temperature for diﬀerent

environment. It supports to read PT100 probe and convert the value to temperature and uplink to IoT server via

LoRaWAN protocol.

LTC2 supports Datalog feature. User can retrieve the sensor value via LoRaWAN downlink command.

LTC2 is powered by 8500mA Li-SOCI2 battery for long time measurement. The battery can run 2~10 years

depends on the network environment and working mode.

Each LTC2 has two internal 24-bit ADC interfacesand are calibrated on 12 set resistors to make sure the

accuracy measurement on wide range.

LTC2 is LoRaWAN v1.0.3 compatible. Each LTC2 is pre-load with a set of unique keys for LoRaWAN registration,

1.2 Features

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User Manual for LoRaWAN End Nodes - LTC2 - LoRaWAN Temperature Transmitter User Manual

• LoRaWAN v1.0.3 Class A

• max: 2 x monitor temperature channels

• Support 3 -wire PT-100

• 8500mAh Li-SOCI2 Battery

• Firmware upgrade via console

• Wall Mountable

• Conﬁgurable via LoRa or UART

• Datalog and retrieve via LoRaWAN

• Use pre-load PT100 probe or 3rd PT100 probe

• Factory calibration for diﬀerent resistance range

• Support accuracy measure of resistance and upload

• Battery Monitoring and upload

• Operation Temperature: -40 ~ 65 ℃

1.3 Applications

• Logistics and Supply Chain Management

• Food management

• Cold chains solution

• Industrial Monitoring and Control

1.4 Hardware Change log

LTC2 v1.0: Release.

1.5 Pin Deﬁnitions and Switch

1.5.1 Jumper JP2 ( Power ON)

Put a jumper on JP2 will power on the LTC2.

1.5.2 LED

The LED will ﬂash in below case.

1. Send an uplink packet



1.5.3 PT100 Interfaces

There are two independent channels to connect 2 x PT100 probes.

Each channel has 3-wire connection for 3-wire PT100 probes.

1.5.4 Reset Button

Press this button will reboot the LTC2

1.6 Probe Variant

LTC2 provide default probe version. See below for the variant:

Model Photo Description

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User Manual for LoRaWAN End Nodes - LTC2 - LoRaWAN Temperature Transmitter User Manual

LTC2-SI Standard IP68 Probe Version

• LTC2 with 1 x Standard IP68 PT100 probe.

• Installation: Insert

• Cable Length : 2m

• PT100 Class : Class A

• Probe Dimension: 4*30mm

• Measure Range: -50 ~ 200 °C

• Suitable Environment: General environment

LTC2-LT Low Temperature Version

• LTC2 with 1 x Low Temperature PT100 probe.

• Installation: Insert

• Cable Length : 2m

• PT100 Class : Class A

• Probe Dimension: 4*30mm

• Measure Range: -196 ~ 150 °C

• Suitable Environment: Low temperature measurement, such as COVID vaccine

transport

LTC2-FS Food Safety Version

• LTC2 with 1 x Food Safety PT100 probe.

• Installation: Insert

• Cable Length : 2m

• PT100 Class : Class A

• Probe Dimension: 4*150mm

• Measure Range: -50 ~ 200 °C

• Suitable Environment: Food temperature measurement

LTC-FSA Food Safety Version

• LTC2 with 1 x Food Safety PT100 probe.

• Installation: Insert

• Cable Length : 2m

• PT100 Class : Class A

• Probe Dimension: 4*150mm

• Measure Range: -50 ~ 200 °C

• Suitable Environment: Food temperature measurement

LTC2-FT Flat Type Version

• LTC2 with 1 x Flat Type PT100 probe.

• Installation: Attached

• Cable Length : 2m

• PT100 Class : Class A

• Probe Dimension: 8*25mm

• Measure Range: -50 ~ 200 °C

• Suitable Environment: Attached to the measure point.

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User Manual for LoRaWAN End Nodes - LTC2 - LoRaWAN Temperature Transmitter User Manual

LTC2-HT High Temperature Version

• LTC2 with 1 x high temperature PT100 probe.

• Installation: Insert

• Cable Length : 3m

• PT100 Class : Class A

• Probe Dimension: 4*30mm

• Measure Range: -70 ~ 550 °C

Suitable Environment: High Temperature

LTC2-NA No Probe version:

• User can connect to their own PT100 Probe

• Grand Hole: M12

• Suitable Environment:

Connect to customized probe

2. How to use LTC2?

2.1 Connect to PT100 sensors

LTC2 has diﬀerent probe option provided for ordering, if user has LTC2 with probe, just skip this step. If user want

to connect to a 3rd party PT100 probe, please see CONNECT A 3rdPARTY PT100 probe.

2.2 How it works?

The LTC2 is working in LoRaWAN OTAA Class A mode. Each LTC2 is shipped with a worldwide unique set of

OTAA and ABP keys. User needs to input the OTAA or ABP keys in the LoRaWAN network server so to register.

LTC2 will join the LoRaWAN network and start to transmit data. The default period for each uplink is 20 minutes.

On each uplink, LTC2 will check its two ADC Interfaces and get the temperature from the sensor and send out to

server.

2.3 Quick guide to connect to LoRaWAN server (OTAA)

Here is an example for how to join the TTN v3 LoRaWANServer. Below is the network structure, in this demo we

use DLOS8 as LoRaWAN gateway.

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User Manual for LoRaWAN End Nodes - LTC2 - LoRaWAN Temperature Transmitter User Manual

The DLOS8 is already set to connect to TTN. Rest we need to is register the LTC2 to TTN v3:



2.3.1 Step 1: Create a device in TTN with the OTAA keys from LTC2



Below is TTN screen shot:

• Create Application ﬁrst.

• Manually Add a LoRaWAN End Device device. Choose OTAA and MAC v1.0.3

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Input the OTAA keys for LTC2.

Each LTC2 is shipped with a sticker with the default device EUI as below:

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•Input these keys to device portal.

•Choose the Frequency band for this end node.

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•Input APP Key in this page as well.

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User Manual for LoRaWAN End Nodes - LTC2 - LoRaWAN Temperature Transmitter User Manual

Add payload formatter So TTNv3 knows how to parse the LTC2 upload value.

The payload for TTN can be found at below link:ttps://github.com/dragino/dragino-end-node-decoder

2.3.2 Step 2: Power on LTC2

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User Manual for LoRaWAN End Nodes - LTC2 - LoRaWAN Temperature Transmitter User Manual

LTC2 is power oﬀ when ship from factory.

Put a Jumper on JP2 to power on the device.

After power on, LTC2 will auto join to TTN network via the LoRaWAN coverage by DLOS8. After join success,

LTC2 will start to update message to IoT server.

Below is an example uplink message which shows the LTC2 is sending Join Request to TTNv3.

After join successful, LTC2 will send uplink message with the sensor value.

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User Manual for LoRaWAN End Nodes - LTC2 - LoRaWAN Temperature Transmitter User Manual

Above value shows Channel1 detect 25.94 degree. There is no PT100 connected on Channel 2, so it shows

-327.67.

2.4 Uplink Payload

Below is the uplink payload which shows



Size(bytes) 2 1 2 2 4

Value BAT



Status & EXT Channel 1 data Channel 2data Unix TimeStamp

BAT

Ex1: 0x0E3C ⇒ 3644 (mV) = 3.644 V



Status & EXT



•Poll Message Flag: 1: This message is a poll message reply, 0: means this is a normal uplink.

•Sync time OK: 1: Set time

ok，0: N/A. After time SYNC request is send, device will set this bit to 0

until got the time stamp from application server.

•Unix Time Request: 1: Request server downlink Unix time, 0 : N/A. In this mode, LTC2 will set this bit to 1

every 10 day to request a time SYNC. (AT+SYNCMOD to set this)

•EXT: The decode method for Channel 1 data and Channel 2 data

• 0b(0001): Upload PT100 temperature, with 2 decimals, range: -327.67 ~ 327.67 ℃

• 0b(0010): Upload PT100 temperature, with 1 decimals, range:-3276.7 ~ 3276.7 ℃

• 0b(0011): Upload Resistance instead of Temperature, range: -327.67~ 327.67 ohm



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User Manual for LoRaWAN End Nodes - LTC2 - LoRaWAN Temperature Transmitter User Manual

Channel1 data and Channel 2 data



Unix TimeStamp



Refer to Datalog feature.

Example Uplink Payload:

Uplink payload example 1: 0CE9011422EC2D6073E83B

• Bat voltage:0x0CE9 =3305mV

• Ext=0x01

• Channel1 temp=0x1422/100=51.54 ℃

• Channel2 temp=(0xEC2D-65536)/100=-50.75 ℃

• System timestamp=0x6073E83B= 1618208827(UTC)

If payload is: EC2DH : (EC2D & 8000 == 1) , temp = (EC2DH - 65536)/100 = -50.75 ℃

（EC2D & 8000：Judge whether the highest bit is 1, when the highest bit is 1, it is negative）

Uplink payload example 2: 0CED020203FE056073E697

• Bat voltage:0x0CED =3309mV

• Ext=0x02

• Channel1 temp=0x0203/10=515.4 ℃

• Channel2 temp=(0xFE05-65536)/10=-507.5 ℃

• System timestamp=0x6073E697=1618208407(UTC)

If payload is: FE05H : (FE05 & 8000 == 1) , temp = (FE05H - 65536)/100 = 507.5 ℃

（EC2D & 8000：Judge whether the highest bit is 1, when the highest bit is 1, it is negative）

Uplink payload example 3 : 0CE9032EDE1F406073E967

• Bat voltage:0x0CE9 =3305mV

• Ext=0x03

• Channel1 res=0x2EDE/100=119.98 ohm

• Channel2 res=0x1F40/100=80.00 ohm

• System timestamp=0x6073E967= 1618209127(UTC)

2.5 Datalog Feature

LTC2 will auto get the time from LoRaWAN server during Join, and each uplink will then include a timestamp.

When user want to retrieve sensor value, user can send a poll command from the IoT platform to ask sensor to send

value in the required time slot.

2.5.1 Unix TimeStamp

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User Manual for LoRaWAN End Nodes - LTC2 - LoRaWAN Temperature Transmitter User Manual

LTC2 uses Unix TimeStamp format based on

Users can get this time from the link: https://www.epochconverter.com/ :

Below is the converter example

So, we can use AT+TIMESTAMP=1611889405 or downlink 3060137afd00 to set current time 2021 – Jan -- 29

Friday 03:03:25

2.5.2 Set Device Time

There are two ways to set the device's time:

1. Through LoRaWAN MAC Command (Default settings)

Users need to set SYNCMOD=1 to enable sync time via the MAC command.

Once LTC2 Joined LoRaWAN network, it will send the MAC command (DeviceTimeReq) and server will reply

with (DeviceTimeAns) to send the current time to LTC2. If LTC2 fails to get the time from server, LTC2 will use the

internal time and wait for next time request (AT+SYNCTDC to set time request period, default is 10 days).



Note: LoRaWAN Server needs to support LoRaWAN v1.0.3(MAC v1.0.3)or higher to support this MAC command

feature, Chirpstack,TTNv3 and loriot support but TTN v2 doesn't support. If server doesn't support this command,

it will through away uplink packet with this command, so user will lose the packet with time request for TTN v2 if

SYNCMOD=1.



2. Manually Set Time

Users need to set SYNCMOD=0 to manual time, otherwise, the user set time will be overwritten by the time set by

the server.

2.5.3 Poll sensor value

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Users can poll sensor values based on timestamps. Below is the downlink command.

Downlink Command to poll Open/Close status (0x31)

1byte 4bytes 4bytes 1byte

31 Timestamp start Timestamp end Uplink Interval



Timestamp start and Timestamp end use Unix TimeStamp format as mentioned above. Devices will reply with all

data log during this time period, use the uplink interval.

For example, downlink command 

Is to check 2021/5/16 01:00:00 to 2021/5/16 02:00:00's data

Uplink Internal =10s，means LTC2 will send one packet every 10s. range 5~255s.

2.5.4 Datalog Uplink payload

When server senser a datalog polling to LTC2, LTC2 will reply with one or more uplink messages as reply. Each

uplink message includes multiply data entries value. Each entry has the same payload format asnormal uplink

payload.

Note:

• Poll Message Flag is set to 1.

• Each data entry is 11 bytes, to save airtime and battery, devices will send max bytes according to the current

DR and Frequency bands.

For example, in US915 band, the max payload for diﬀerent DR is:

1. DR0:max is 11 bytes so one entry of data

2. DR1: max is 53 bytes so devices will upload 4 entries of data (total 44 bytes)

3. DR2: total payload includes 11 entries of data

4. DR3: total payload includes 22 entries of data.

If devise doesn't have any data in the polling time. Device will uplink 11 bytes of 0

Example:

If LTC2 has below data inside Flash:

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User Manual for LoRaWAN End Nodes - LTC2 - LoRaWAN Temperature Transmitter User Manual

If user send below downlink command:

3160A06E9060A098C00A

Where : Start time: 60A06E90 = time 21/5/16 01:00:00

Stop time: 60A098C0 = time 21/5/16 04:00:00

LTC2 will uplink this payload.

0E64410B49800160A072B80E61410B3F800160A077680E61410B33800160A07C180E64410B2C800160A080C80E64410B28800160A085780E64410B24800160A08A280E64410B23800160A08ED80E64410B22800160A093880E64410B1E800160A09838

Where the ﬁrst 11 bytes is for the ﬁrst entry:

0E64410B49800160A072B8

Bat voltage:0x0E64 =3684mV

poll message ﬂag & Ext=0x41,means reply data,Ext=1

Channel1 temp=0x0B49/100=28.89℃

Channel2 temp=0x8001/100=-327.67℃

System timestamp=0x60A072B8= 1621127864(UTC)

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