PS-KN

PS-KN – NB-IoT Analog Sensor

1. Introduction

1.1 What is NB-IoT Analog Sensor

The Dragino PS-KN is a NB-IoT Analog Sensor for Internet of Things solution. PS-KN has 5v and 12v output, 420mA, 030v input interface to power and get value from Analog Sensor. PS-KN will convert the Analog Value to NB-IoT wireless data and send to IoT platform via NB-IoT network.

PS-KN supports different uplink methods including MQTT, MQTTs, UDP ,TCP&CoAP for different application requirement, and support uplinks to various IoT Servers.

PS-KN supports BLE configure and OTA update which make user easy to use.

PS-KN is powered by DC Power + 1000mAh BackUp Battery, it is designed for long-term use up to several years.

PS-KN has optional built-in SIM card and default IoT server connection version. Which makes it works with simple configuration.

1.2 Features

• NB-IoT Bands: B1/B2/B3/B4/B5/B7/B8/B20/B28/B34/B27/B28/B38/B39/B40/B41/B66
• Ultra-low power consumption
• 1 x 020mA input , 1 x 030v input
• 5v and 12v output to power external sensor
• Multiply Sampling and one uplink
• Support Bluetooth v5.1 remote configure and update firmware
• Uplink on periodically
• Downlink to change configure
• Solar panel + 3000mAh Li-ion Battery (PS-KS)
• Charging Pad + 1000mAh Li-ion Battery (PS-KN)
• IP66 Waterproof Enclosure
• Uplink via MQTT, MQTTs, TCP, or UDP
• Nano SIM card slot for NB-IoT SIM

1.3 Specification

Common DC Characteristics:

• Supply Voltage: 2.5v ~ 3.6v
• Operating Temperature: -40 ~ 85°C

Current Input (DC) Measuring :

• Range: 0 ~ 20mA
• Accuracy: 0.02mA
• Resolution: 0.001mA

Voltage Input Measuring:

• Range: 0 ~ 30v
• Accuracy: 0.02v
• Resolution: 0.001v

NB-IoT Spec:

NB-IoT Module: EG800-NGFF

Support Bands:

EU:

For European, Asia, Austrial, LTE-FDD: B1/3/5/7/8/20/28

• B1 @FDD: 2100MHz

• B3 @FDD: 1800MHz

• B5 @FDD: 850MHz

• B7 @FDD: 2600MHz

• B8 @FDD: 900MHz

• B20 @FDD: 800MHz

• B28 @FDD: 700MHz

LA:

For Latin America, LTE-FDD: B2/3/4/5/7/8/28/66

• B2 @FDD: 1900MHz

• B3 @FDD: 1800MHz

• B4 @FDD: 1700/2100MHz

• B5 @FDD: 850MHz

• B7 @FDD: 2600MHz

• B8 @FDD: 900MHz

• B28 @FDD: 700MHz

• B66 @FDD: 1700/2100MHz

NA:

For North America, LTE-FDD: B2/4/5/12/13/66

• B2 @FDD: 1900MHz

• B4 @FDD: 1700/2100MHz

• B5 @FDD: 850MHz

• B12 @H-FDD: 720MHz

• B13 @H-FDD: 740MHz

• B66 @FDD: 1700/2100MHz

Battery:

• Li-ion Battery
• Capacity: 3000mAh & 1000mAh
• Self Discharge: <1% / Year @ 25°C
• Max continuously current: 130mA
• Max boost current: 2A, 1 second

Power Consumption

• STOP Mode: 10uA @ 3.3v
• Max transmit power: 350mA@3.3v

1.4 Probe Types

1.4.1 Thread Installation Type

• Hersman Pressure Transmitter
• Measuring Range: -0.1 ~ 0 ~ 60MPa, see order info.
• Accuracy: 0.2% F.S
• Long-Term Stability: 0.2% F.S ±0.05%
• Overload 200% F.S
• Zero Temperature Drift: 0.03% FS/℃(≤100Kpa), 0.02%FS/℃(>100Kpa)
• FS Temperature Drift: 0.003% FS/℃(≤100Kpa), 0.002%FS/℃(>100Kpa)
• Storage temperature: -30℃~80℃
• Operating temperature: -20℃~60℃
• Connector Type: Various Types, see order info

1.4.2 Immersion Type

• Immersion Type, Probe IP Level: IP68
• Measuring Range: Measure range can be customized, up to 100m.
• Accuracy: 0.2% F.S
• Long-Term Stability: ±0.2% F.S / Year
• Storage temperature: -30℃~80℃
• Operating temperature: 0℃~50℃
• Material: 316 stainless steels

1.4.3 Food Safety Thread Type

• Material: Food Grade 316L Stainless Steel, Anti-clogging, Pressure and wear resistant
• Application Scenarios: Measuring viscous media: food and beverages, viscous gels, pigments and paints, pulp and cement, pump trucks, concrete, particulate matter
• Measuring Range: -100Kpa ~ 0 ~ 100MPa
• Compensation Temperature: 10 ~ 70°C
• Output Signal: 4 ~ 20mA
• Power Supply: 24V DC
• Ambient Temperature: -40 ~ 85°C
• Enclosure Protection: IP65
• Pressure Type: Gauge pressure, Absolute pressure, Sealed pressure
• Zero-point Temperature Drift: +0.03%FS/°C
• Sensitivity Temperature Drift: +0.03%FS/°C
• Overload Pressure: 200%FS
• Long-term Stability: ≤0.2%FS/°C
• Natural Frequency: 5HZ ~ 650HZ

1.4.4 Wireless Differential Air Pressure Sensor

• easuring Range: -100Pa ~ 100KPa(Optional measuring range).
• Accuracy: 0.5% F.S, resolution is 0.05%.
• Overload: 300% F.S
• Zero temperature drift: ±0.03%F.S/°C
• Operating temperature: -20°C~60°C
• Storage temperature: -20°C~60°C
• Compensation temperature: 0~50°C

1.5 Application and Installation

1.5.1 Thread Installation Type

Application:

• Hydraulic Pressure
• Petrochemical Industry
• Health and Medical
• Food & Beverage Processing
• Auto-controlling house
• Constant Pressure Water Supply
• Liquid Pressure measuring

Order the suitable thread size and install to measure the air / liquid pressure

1.5.2 Immersion Type

Application:

Liquid & Water Pressure / Level detect.

The Immersion Type pressure sensor is shipped with the probe and device separately. When user got the device, below is the wiring to for connect the probe to the device.

Size of immersion type water depth sensor:

1.5.3 Food Safety Thread Type

Application:

• Milk Oil Storage Tank Monitoring
• Pigment And Paint Storage Monitoring
• Pulp & Cement Storage
• Concrete Pump Truck

1.5.4 Wireless Differential Air Pressure Sensor

Application:

Indoor Air Control & Filter clogging Detect.

Below is the wiring to for connect the probe to the device.

Size of wind pressure transmitter:

Note: The above dimensions are measured by hand, and the numerical error of the shell is within ±0.2mm.

1.6 Sleep mode and working mode

Deep Sleep Mode: Sensor doesn't have any NB-IoT activate. This mode is used for storage and shipping to save battery life.

Working Mode: In this mode, Sensor will work as NB-IoT Sensor to Join NB-IoT network and send out sensor data to server. Between each sampling/tx/rx periodically, sensor will be in IDLE mode), in IDLE mode, sensor has the same power consumption as Deep Sleep mode.

1.7 Button & LEDs

Behavior on ACT	Function	Action
1~3s	Send an uplink	If sensor has already attached to NB-IoT network, sensor will send an uplink packet, blue led will blink once. Meanwhile, BLE module will be active and user can connect via BLE to configure device.
>3s	Active Device	Green led will fast blink 5 times, device will enter OTA mode for 3 seconds. And then start to attach NB-IoT network. Once sensor is active, BLE module will be active and user can connect via BLE to configure device, no matter if device attach NB-IoT network or not.
x5	Deactivate Device	Red led will solid on for 5 seconds. Means device is in Deep Sleep Mode.

Note: When the device is executing a program, the buttons may become invalid. It is best to press the buttons after the device has completed the program execution.

1.8 BLE connection

PS-KN support BLE remote configure and firmware update.

BLE can be used to configure the parameter of sensor or see the console output from sensor. BLE will be only activate on below case:

• Press button to send an uplink
• Press button to active device.
• Device Power on or reset.

If there is no activity connection on BLE in 60 seconds, sensor will shut down BLE module to enter low power mode.

1.9 Pin Definitions , Switch & SIM Direction

PS-KN use the mother board which as below.

1.9.1 Jumper JP2

Power on Device when put this jumper.

1.9.2 BOOT MODE / SW1

1. ISP: upgrade mode, device won't have any signal in this mode. but ready for upgrade firmware. LED won't work. Firmware won't run. 2) Flash: work mode, device starts to work and send out console output for further debug

1.9.3 Reset Button

Press to reboot the device.

1.9.4 SIM Card Direction

See this link. How to insert SIM Card.

1.10 Mechanical

1.10.1 For KN Version

1.10.2 For KS Version

2. Use PS-KN to communicate with IoT Server

2.1 Send data to IoT server via NB-IoT network

The PS-KN is equipped with a NB-IoT module, the pre-loaded firmware in PS-KN will get environment data from sensors and send the value to local NB-IoT network via the NB-IoT module. The NB-IoT network will forward this value to IoT server via the protocol defined by PS-KN.

Below shows the network structure:

There are two version: -GE and -1T version of PS-KN. GE Version: This version doesn't include SIM card or point to any IoT server. User needs to use AT Commands to configure below two steps to set PS-KN send data to IoT server.

• Install NB-IoT SIM card and configure APN. See instruction of Attach Network.

• Set up sensor to point to IoT Server. See instruction of Configure to Connect Different Servers.

Below shows result of different server as a glance.

Servers	Dash Board	Comments
Node-Red
DataCake
Tago.IO
General UDP	Raw Payload. Need Developer to design Dash Board
General MQTT	Raw Payload. Need Developer to design Dash Board
ThingSpeak
ThingsBoard

1T Version: This version has 1NCE SIM card pre-installed and configure to send value to ThingsEye. User Just need to select the sensor type in ThingsEyeand Activate PS-KN and user will be able to see data in ThingsEye. See here for ThingsEye Config Instruction.

2.2 Payload Types

To meet different server requirement, PS-KN supports different payload type.

Includes:

• General JSON format payload. (Type=5)

• HEX format Payload. (Type=0)

• ThingSpeak Format. (Type=1)

• ThingsBoard Format. (Type=3)

User can specify the payload type when choose the connection protocol. Example:

AT+PRO=2,0 // Use UDP Connection & hex Payload

AT+PRO=2,5 // Use UDP Connection & Json Payload

AT+PRO=3,0 // Use MQTT Connection & hex Payload

AT+PRO=3,1 // Use MQTT Connection & ThingSpeak

AT+PRO=3,3 // Use MQTT Connection & ThingsBoard

AT+PRO=3,5 // Use MQTT Connection & Json Payload

AT+PRO=4,0 // Use TCP Connection & hex Payload

AT+PRO=4,5 // Use TCP Connection & Json Payload

The following describes the latest payload.

2.2.1 General Json Format(Type=5)

This is the General Json Format. As below:

{"IMEI":"867586073737165","IMSI":"901405101775407","Model":"PS-KS","idc_input":21.514,"vdc_input":3.366,"interrupt":0,"interrupt_level":0,"battery":3.430,"signal":25,"idc_alarm":"NULL","vdc_alarm":"NULL","time":"2026-07-02T06:56:48Z","1":[0.000,0.000,"2106-02-06T06:28:15Z"],"2":[0.000,1.941,"2106-02-06T06:28:15Z"],"3":[0.000,0.000,"2106-02-06T06:28:15Z"],"4":[0.000,0.000,"2106-02-06T06:28:15Z"],"5":[0.000,0.000,"2106-02-06T06:28:15Z"],"6":[0.000,0.000,"2106-02-06T06:28:15Z"],"7":[0.000,0.000,"2106-02-06T06:28:15Z"],"8":[0.000,0.000,"2106-02-06T06:28:15Z"]}

Notice, from above payload:

• idc_input, vdc_input, battery, signal, idc_alarm, vdc_alarm & time are the value at uplink time.

• Json entry 1 ~ 8 are the last 1 ~ 8 sampling data as specify by AT+CLOCKLOG=1,65535,15,8 Command. Each entry includes (from left to right): Idc_input , Vdc_input, Sampling time.

• For idc_alarm and vdc_alarm, there are three possible states:

  ①When the uplink packet is not triggered by a ROC alarm, the status will be NULL.

  ②When the uplink packet is triggered by a ROC alarm due to incremental change exceeding the threshold, the status will be:

  "idc_alarm": "IDC_INC"

  "vdc_alarm": "IDC_INC"

  ③When the uplink packet is triggered by a ROC alarm due to decremental change exceeding the threshold, the status will be:

  "idc_alarm": "IDC_DEC"

  "vdc_alarm": "VDC_DEC"

2.2.2 HEX format Payload(Type=0)

This is the HEX Format. As below:

f863663062798914f460087023300073017d0ccb1600000000000100000000195a687890ca0000000068788bbb000000006878883700000000687884b3000000006878812f0000000068787dab0000000068787a2700000000687876a300001d4168787321

Device ID(f+IMEI): f867586073737165 = 867586073737165

SIM Card ID(f+IMSI): f901405101775407 = 901405101775407

Version:

These bytes include the hardware and software version.

Higher byte: Specify Sensor Model: 0x46 for PS-KN

Lower byte: Specify the software version: 0x65(H) = 101(D), means firmware version 1.0.1

BAT (Battery Info):

Check the battery voltage for PS-KN.

Ex1: 0x0d43 = 3395mV

Ex2: 0x0B49 = 2889mV

Signal Strength:

NB-IoT Network signal Strength.

Ex1: 0x1a = 26

0 -113dBm or less

1 -111dBm

2...30 -109dBm... -53dBm

31 -51dBm or greater

99 Not known or not detectable

IN1 & IN2:

IN1 and IN2 are used as Digital input pins.

Example:

01 (H): IN1 or IN2 pin is high level.

00 (L): IN1 or IN2 pin is low level.

GPIO_EXTI Level:

GPIO_EXTI is used as Interrupt Pin.

Example:

01 (H): GPIO_EXTI pin is high level.

00 (L): GPIO_EXTI pin is low level.

GPIO_EXTI Flag:

This data field shows if this packet is generated by Interrupt Pin or not.

Note: The Interrupt Pin is a separate pin in the screw terminal.

Example:

0x00: Normal uplink packet.

0x01: Interrupt Uplink Packet.

idc_roc_alarm

This data field indicates whether the uplink data packets are generated by the IDC's ROC alarm.

Example:

0x00: Normal uplink packet.

0x01: Uplink message triggered by ROC alarm due to incremental change exceeding the threshold.

0x02: Uplink message triggered by ROC alarm due to decremental change exceeding the threshold.

vdc_roc_alarmv

This data field indicates whether the uplink data packets are generated by the VDC's ROC alarm.

Example:

0x00: Normal uplink packet.

0x01: Uplink message triggered by ROC alarm due to incremental change exceeding the threshold.

0x02: Uplink message triggered by ROC alarm due to decremental change exceeding the threshold.

Probe Model:

PS-KN might connect to different kind of probes, 4~20mA represent the full scale of the measuring range. So a 12mA output means different meaning for different probe.

For example.

Probe Type	4~20mA scale for this probe	Example: 12mA actually meaning for this probe
PH Combination Electrodes	0 ~ 14 pH	PH Value: 7
Water Pressure Sensor	0~5 meters	2.5 meters pure water
Pressure transmitter probe	0~1MPa	0.5MPa air / gas or water pressure

User can set different probe model for above probes. So IoT server is able to se identical how it should parse the 4~20mA or 0~30v sensor value and get the correct value.

0~20mA:

Example:

540a(H) = 21514 (D)/1000 = 21.514mA.

Connect to a 2 wire 4~20mA sensor.

0~30V:

Measure the voltage value. The range is 0 to 30V.

Example:

0d2f(H) = 3375(D)/1000= 3.375V

TimeStamp:

Unit TimeStamp Example: 6a460d03(H) = 1782975747(D)

Put the decimal value into this link( Epoch Converter )to get the time.

2.2.3 ThingsBoard Payload(Type=3)

Type3 payload special design for ThingsBoard, it will also configure other default server to ThingsBoard.

{ "topic": "004_NB", "payload": { "IMEI": "863663062798815", "IMSI": "460083513507309", "Model": "PS-KN", "idc_intput": 0.0, "vdc_intput": 0.0, "battery": 3.584, "signal": 23, "time": "2024/12/17 03:37:25", "1": [0.273, 0.443, "2024/08/26 09:40:35"], "2": [0.275, 0.442, "2024/08/26 07:39:55"], "3": [0.281, 0.554, "2024/08/23 09:49:04"], "4": [0.276, 0.554, "2024/08/23 09:13:40"], "5": [0.256, 0.0, "2024/08/23 08:58:40"], "6": [0.0, 0.003, "2024/08/23 08:43:40"], "7": [0.278, 0.528, "2024/08/23 08:28:40"], "8": [1.3, 0.0, "2024/08/23 07:48:31"] } }

2.3 Test Uplink and Change Update Interval

By default, sensor will send uplinks every 2 hours

User can use below commands to change the uplink interval.

AT Command: AT+TDC

Example: AT+TDC=7200 // Set Update Interval to 7200 seconds

Downlink Command: 0x01

Format: Command Code (0x01) followed by 3 bytes.

Example: 12 hours= 43200 seconds 43200(D)=0xA8C0(H)

Downlink Payload: 01 00 A8 C0 // AT+TDC=43200, Set Update Interval to 12 hours.

Note: User can also push the button for more than 1 second to activate an uplink.

2.4 Multi-Samplings and One uplink(It is replaced by AT+CLOCKLOG

Sometimes when we deploy lots of end nodes in field. We want all sensors sample data at the same time, and upload these data together for analyze. In such case, we can use clock loging feature.

We can use this command to set the start time of data recording and the time interval to meet the requirements of the specific collection time of data.

• AT Command: AT+CLOCKLOG=a,b,c,d

a: 0: Disable Clock logging. **1:**Enable Clock Logging

b: Specify First sampling start second: range (0 ~ 3599, 65535) // **Note:**If parameter b is set to 65535, the log period starts after the node accesses the network and sends packets.

c: Specify the sampling interval: range (0 ~ 255 minutes)

d: How many entries should be uplink on every TDC (max 32)

Note: To disable clock recording, set the following parameters: AT+CLOCKLOG=1,65535,0,0

Example:

AT+CLOCKLOG=1,65535,1,8

After the node sends the first packet, data is recorded to the memory at intervals of 1 minute. For each TDC uplink, the uplink load will include: battery information + the last 8 memory records (payload + timestamp).

Note: Users need to synchronize the server time before configuring this command. If the server time is not synchronized before this command is configured, the command takes effect only after the node is reset.

• Downlink command: 0x03

Format: Command Code (0x03) followed by 5 bytes.

• Example 1: Downlink Payload:0301FFFF0F08 // Set SHT record time: AT+CLOCKLOG=1,65535,15,8
• Example 1: Downlink Payload:030104B00F08 // Set SHT record time: AT+CLOCKLOG=1,1200,15,8

Note: When entering the downlink payload, there must be no Spaces between bytes.

2.5 Trggier an uplink by external interrupt

PS-KN has an external trigger interrupt function. Users can use the GPIO_EXTI pin to trigger the upload of data packets.

AT command:

• AT+INTMOD // Set the trigger interrupt mode

• AT+INTMOD=0 // Disable Interrupt,as a digital input pin

• AT+INTMOD=1 // Trigger by rising and falling edge

• AT+INTMOD=2 // Trigger by falling edge

• AT+INTMOD=3 // Trigger by rising edge

2.6 Set Power Output Duration

Control the output duration 3V3 , 5V or 12V. Before each sampling, device will

1. first enable the power output to external sensor,

2. keep it on as per duration, read sensor value and construct uplink payload

3. final, close the power output.

• Set extend the time of 3V3 power:

AT Command: AT+3V3T

Command Example	Function	Response
AT+3V3T=?	Show 3V3 open time.	0 OK
AT+3V3T=0	Normally open 3V3 power supply.	OK default setting
AT+3V3T=1000	Close after a delay of 1000 milliseconds.	OK
AT+3V3T=65535	Normally closed 3V3 power supply.	OK

Downlink Command: 0x0701

Example 1: Downlink Payload: 070101F4 --> AT+3V3T=500

Example 2: Downlink Payload: 0701FFFF --> AT+3V3T=65535

• Set extend the time of 5V power:

AT Command: AT+5VT

Command Example	Function	Response
AT+5VT=?	Show 5V open time.	0 OK
AT+5VT=0	Normally closed 5V power supply.	OK default setting
AT+5VT=1000	Close after a delay of 1000 milliseconds.	OK
AT+5VT=65535	Normally open 5V power supply.	OK

Downlink Command: 0x0702

Example 3: Downlink Payload: 070203E8 --> AT+5VT=1000

Example 4: Downlink Payload: 07020000 --> AT+5VT=0

• Set extend the time of 12V power:

AT Command: AT+12VT

Command Example	Function	Response
AT+12VT=?	Show 12V open time.	0 OK
AT+12VT=0	Normally closed 12V power supply.	OK
AT+12VT=500	Close after a delay of 500 milliseconds.	OK
AT+12VT=65535	Normally open 5V power supply.	OK

Downlink Command: 0x0703

Example 5: Downlink Payload: 070301F4 --> AT+12VT=500

Example 6: Downlink Payload: 07030000 --> AT+12VT=0

2.7 Set the Probe Model

Users need to configure this parameter according to the type of external probe. In this way, the server can decode according to this value, and convert the current value output by the sensor into water depth or pressure value.

AT Command: AT+PROBE

AT+PROBE=aabb

When aa=00, it is the water depth mode, and the current is converted into the water depth value; bb is the probe at a depth of several meters.

When aa=01, it is the pressure mode, which converts the current into a pressure value;

bb represents which type of pressure sensor it is.

Command Example	Function	Response
AT +PROBE =?	Get or Set the probe model.	0 OK
AT +PROBE =0003	Set water depth sensor mode, 3m type.	OK
AT +PROBE =000A	Set water depth sensor mode, 10m type.	OK
AT +PROBE =0101	Set pressure transmitters mode, first type.	OK
AT +PROBE =0000	Initial state, no settings.	OK

• Downlink command: 0x0A

Format: Command Code (0x08) followed by 2 bytes.

• Example 1: Downlink Payload: 080003 ---> AT+PROBE=0003
• Example 2: Downlink Payload: 080101 ---> AT+PROBE=0101

Note: When entering the downlink payload, there must be no Spaces between bytes.

2.8 Datalog Function

Datalog Retransmission Function

Description:

The PS-KN supports data retransmission after offline recovery. When the device is offline, it continues to store data locally based on the sampling interval configured by AT+CLOCKLOG. Once the network is reconnected, the device will retransmit the stored data, with a maximum capacity of 1504 data sets.

AT Command:

AT+REDPT – Get or Set the data retransmission function after reconnecting to the network.

Command Example	Function	Response
AT+REDPT=?	Query current retransmission status	0 (default)ok
AT+REDPT=0	Disable retransmission	ok
AT+REDPT=1	Enable retransmission (max 1504 sets)	ok

Downlink Command:

No downlink commands for this feature.

Note:

• Retransmission applies only to data stored during offline periods.
• The retransmission data format aligns with the data format set via AT+PRO, supporting both HEX and JSON formats.

Example:

• HEX format

The retransmitted HEX-formatted datalog is consistent with the datalog data format queried via the 0x31 command, with each data group comprising 8 bytes:

Size(bytes)	2	2	4
value	0~20mA	0~30V	Timestamp

• JSON format

When setting the payload format of AT+PRO to JSON, only the retransmitted datalog data uses the same JSON format as normal uplink data. The datalog queried via 0x31 is only available in HEX format.

2.10 Example Query saved historical records

• AT command: AT+CDP

This command can be used to search the saved history, recording up to 32 groups of data, each group of historical data contains a maximum of 100 bytes.

2.11 Scheduled domain name resolution

This command is used to set up scheduled domain name resolution.

AT command:

• AT+DNSTIMER// Unit: hour

After setting this command, domain name resolution will be performed regularly.

2.12 Set the QoS level

This command is used to set the QoS level of MQTT.

AT command:

• AT+MQOS// 0~2

Downlink command: 0x07

Format: Command Code (0x07) followed by 1 byte.

Ex1: Downlink payload: 0x0200 // AT+MQOS=0

Ex2: Downlink payload: 0x0201 // AT+MQOS=1

2.13 Set the downlink debugging mode

Feature: Enable or disable downlink debugging mode.

AT command: AT+DOWNTE

Command Example	Function/Parameters	Response/Explanation
AT+DOWNTE=?	Get current Settings	0,0 (default) OK
AT+DOWNTE=0,a	a: Enable/Disable downlink debugging	0: Disable downlink debugging mode. 1: Enable downlink debugging mode (users can view original downlink messages).

(Note: The first parameter is fixed to 0 and only the second parameter is configurable.)

Example:

• AT+DOWNTE=0,1 → Enable downlink debugging mode.
• AT+DOWNTE=0,0 → Disable downlink debugging mode.

Downlink Command:

No downlink commands for feature

2.14 Domain name resolution settings

Feature: Set dynamic domain name resolution IP.

AT command: AT+BKDNS

Command Example	Function/Parameters	Response/Explanation
AT+BKDNS=?	Get current Settings	0,0,NULL  (default) OK
AT+BKDNS=a,b,c	a : Enable/Disable dynamic domain name resolution.	1 : Disable dynamic domain name update. The ip address will be saved after the domain name is resolved, if the next domain name resolution fails, the last saved ip address will be used. 2 : Enable dynamic domain name update. The ip address will be saved after domain name resolution, if the next domain name resolution fails, the last saved ip address will be used, and the domain name resolution will be updated regularly according to the time set by the customer.
	b : Set the time to update the domain name resolution at regular intervals.	Unit: hour
	c : Set the IP address manually.	The format is the same as AT+SERVADDR. If domain name resolution fails, this ip address will be used directly, if domain name resolution succeeds, parameter c will be updated to the successfully resolved IP address.

Example:

• AT+BKDNS=1,0        // Dynamic domain name resolution is disabled.
• AT+BKDNS=2,1        // The dynamic domain name resolution function is enabled and the automatic update time is set to 1 hour.
• AT+BKDNS=2,4,3.69.98.183,1883     // The dynamic domain name resolution function is enabled and the automatic update time is set to 4 hour, and manually set the ip address, if the domain name failed to resolve, it will directly use this ip to communicate. When the next domain name resolution is successful, it will be updated to the ip address of the successful resolution.

Downlink Command:

No downlink command for this feature

2.15 Print last few data entries

Feature: Print the last few data entries

AT command: AT+PLDTA

Command Example	4 bytes
AT+PLDTA=5 Print last 5 entries	Stop Tx events when read sensor data 1 26/7/2 07:57:03 idc_input=21.514 vdc_input=3.348 2 26/7/2 07:58:03 idc_input=21.514 vdc_input=3.350 3 26/7/2 07:59:03 idc_input=21.514 vdc_input=3.364 4 26/7/2 08:00:03 idc_input=21.514 vdc_input=3.348 5 26/7/2 08:01:03 idc_input=21.514 vdc_input=3.350 OK

Downlink Command:

No downlink command for this feature

2.16 Print data entries base on page

Feature: Print the sector data from start page to stop page.

AT command: AT+PDTA

Command Example

4 bytes

AT+PDTA=1,1 Print page 1 to 1

Stop Tx events when read sensor data 8028A00 26/3/19 10:16:19 idc_input=0.000 vdc_input=0.000 8028A08 26/3/19 10:31:19 idc_input=0.000 vdc_input=0.000 8028A10 26/3/19 10:46:19 idc_input=0.000 vdc_input=0.000 8028A18 26/3/19 11:01:19 idc_input=0.000 vdc_input=0.000 8028A20 26/3/19 11:16:19 idc_input=0.000 vdc_input=0.000 8028A28 26/3/19 11:31:19 idc_input=0.000 vdc_input=0.000 8028A30 26/3/19 11:46:19 idc_input=0.000 vdc_input=0.000 8028A38 26/3/19 12:01:19 idc_input=0.000 vdc_input=0.000 8028A40 26/3/19 12:16:19 idc_input=0.000 vdc_input=0.000 8028A48 26/3/19 12:31:19 idc_input=0.000 vdc_input=0.000 8028A50 26/3/19 12:46:19 idc_input=0.000 vdc_input=0.000 8028A58 26/3/19 13:01:19 idc_input=0.000 vdc_input=0.000 8028A60 26/3/19 13:16:19 idc_input=0.000 vdc_input=0.000 8028A68 26/3/19 13:31:19 idc_input=0.000 vdc_input=0.000 8028A70 26/3/19 13:46:19 idc_input=0.000 vdc_input=0.000 8028A78 26/3/19 14:01:19 idc_input=0.000 vdc_input=0.00 OK

Downlink Command:

No downlink command for this feature

2.17 Clear Flash Record

Feature: Clear flash storage for data log feature.

AT command: AT+CLRDTA

Command Example	Function	Response
AT+CLRDTA	Clear date record	Stop Tx events,Please wait for the erase to complete Clear all stored sensor data... Start Tx events OK

Downlink Command: 0x32

• Example: 0x32 00 // Same as AT+CLRDTA

2.18 Set device auto-reset time

Feature: Configure the device to automatically reset after a specified number of hours(Range: 0~255). AT command: AT+RESETTIME

Command Example	Function/Parameters	Response
AT+RESETTIME=?	Get current settings	0 OK
AT+RESETTIME=	Set auto-reset timer (in hours). 0: Disable auto-reset. >0: Reset after specified hours.	OK

Example:

• AT+RESETTIME=24 // Device will reset every 24 hours.
• AT+RESETTIME=0 // Disable auto-reset (default).

Downlink Command:

No downlink command for this feature.

2.19 Set failure-triggered reset

Feature: Configure the number of consecutive failed transmission cycles (TDC periods) required to trigger an automatic device reset. (Each TDC period includes up to 3 transmission attempts.)

AT command: AT+FAILNUMB

Command Example	Function/Parameters	Response
AT+FAILNUMB=?	Get current settings	2 (default) OK
AT+FAILNUMB=	Set failure threshold: 0: Disable auto-reset function. 1-255: Number of consecutive failed TDC cycles to trigger reset.	OK

Detailed Behavior:

• Each TDC period allows up to 3 transmission attempts for a single data packet.
• A "failed TDC cycle" means all 3 transmission attempts within that cycle failed.
• When the number of consecutive failed TDC cycles reaches the set threshold, the device will automatically reset.

Example:

• AT+FAILNUMB=0: Disables auto-reset (device will never reset due to transmission failures).
• AT+FAILNUMB=1: Device resets after 2 consecutive failed TDC cycles (total 6 failed attempts: 3 attempts × 2 cycles).
• AT+FAILNUMB=2: Device resets after 3 consecutive failed TDC cycles (total 9 failed attempts: 3 attempts × 3 cycles) - Default setting.
• AT+FAILNUMB=3: Device resets after 4 consecutive failed TDC cycles (total 12 failed attempts).

Note:

• The counter resets after any successful transmission.
• Maximum settable value is 255 (would require 256 consecutive failed TDC cycles to trigger reset).

Downlink Command:

No downlink command for this feature.

2.20 Report on Change Feature

Function Overview

The ROC feature monitors changes in IDC (current) and VDC (voltage) by setting a detection interval and change thresholds. When changes exceed the configured thresholds, the device sends an ROC uplink message and refreshes the comparison value.

AT Command Syntax

• AT+ROC=? // Query current ROC settings
• AT+ROC=0,0,0,0 // Disable ROC function
• AT+ROC=1,[interval],[idc_threshold],[vdc_threshold] // Enable ROC mode 1
• AT+ROC=2,[interval],[idc_threshold],[vdc_threshold] // Enable ROC mode 2

Parameters

Mode (first parameter)

0: Function disabled.

1: ROC mode 1 - Sends ROC uplink and refreshes comparison value when change exceeds threshold.

2: ROC mode 2 - Additionally refreshes comparison value during regular transmissions (TDC, manual, etc.).

interval

Detection interval in seconds (0~65535).

idc_threshold

Current change threshold in microamperes (μA).

vdc_threshold

Voltage change threshold in millivolts (mV).

Mode Differences

Mode 1: Only updates comparison value when ROC threshold is exceeded.

Mode 2: Updates comparison value both when threshold is exceeded and during regular transmissions (TDC, manual, etc.).

AT Command Examples

• AT+ROC=1,60,3000,500 //Checks every 60 seconds. Sends ROC uplink if current changes >3000μA (3mA) or voltage changes >500mV, then refreshes comparison values.
• AT+ROC=1,60,3000,0 //Checks every 60 seconds. Only monitors current changes (>3mA). Setting vdc_threshold=0 disables voltage monitoring.
• AT+ROC=2,120,3000,500 //Checks every 120 seconds. Sends ROC uplink if current changes >3000μA (3mA) or voltage changes >500mV. Refreshes comparison value both when threshold is exceeded and during regular transmissions.
• AT+ROC=2,120,0,500 //Checks every 120 seconds for voltage changes (>500mV). Refreshes comparison value both when threshold is exceeded and during regular transmissions.

Downlink Command Format(8 bytes)

Structure: 0x09 aa bb bb cc cc dd dd

Byte Position	Field	Description	Example Values
1	Function Code	Always 0x09 for ROC configuration.	09
2	a: Mode	00: OFF 01: Mode 1 02: Mode 2	01 //ROC mode 1
3-4	b: Interval	Detection interval in seconds.	00 3C //60s
5-6	c: IDC Threshold	Current change threshold in μA.	0B B8 //3000μA
7-8	d: VDC Threshold	Voltage change threshold in mV.	01 F4 //500mV

Downlink Examples

• 09 01 00 3C 0B B8 01 F4 //Equivalent to AT+ROC=1,60,3000,500
• 09 02 00 78 00 00 01 F4 //Equivalent to AT+ROC=2,120,0,500
• 09 02 00 78 0B B8 01 F4 //Equivalent to AT+ROC=2,120,3000,500

3. Configure PS-KN

3.1 Configure Methods

PS-KN supports below configure method:

• AT Command via Bluetooth Connection (Recommended): BLE Configure Instruction.

• AT Command via UART Connection : See UART Connection.

3.2 Serial Access Password

After the Bluetooth or UART connection is successful, use the Serial Access Password to enter the AT command window.

The label on the box of the node will print the initial password: AT+PIN=xxxxxx, and directly use the six-digit password to access the AT instruction window.

If you need to change the password, use AT+PWORD=xxxxxx (6 characters), NB nodes only support lowercase letters.

Note: After entering the command, you need to add a line break, and you can also set automatic line breaks in the Bluetooth tool or UART connection tool.

3.3 AT Commands Set

AT+<CMD>? : Help on <CMD>

AT+<CMD> : Run <CMD>

AT+<CMD>=<value> : Set the value

AT+<CMD>=? : Get the value

General Commands

AT : Attention

AT? : Short Help

ATZ : MCU Reset

AT+TDC : Application Data Transmission Interval

AT+CFG : Print all configurations

AT+MODEL :Get module information

AT+SLEEP :Get or set the sleep status

AT+DEUI : Get or set the Device ID

AT+INTMOD : Set the trigger interrupt mode

AT+APN : Get or set the APN

AT+3V3T : Set extend the time of 3V3 power

AT+5VT : Set extend the time of 5V power

AT+12VT : Set extend the time of 12V power

AT+PROBE : Get or Set the probe model

AT+PRO : Choose agreement

AT+RXDL : Extend the sending and receiving time

AT+TR : Get or set data record time

AT+CDP : Read or Clear cached data

AT+NOUD : Get or Set the number of data to be uploaded

AT+DNSCFG : Get or Set DNS Server

AT+CSQTIME : Get or Set the time to join the network

AT+DNSTIMER : Get or Set the NDS timer

AT+TLSMOD : Get or Set the TLS mode

AT+GETSENSORVALUE : Returns the current sensor measurement

AT+SERVADDR : Server Address

MQTT Management

AT+CLIENT : Get or Set MQTT client

AT+UNAME : Get or Set MQTT Username

AT+PWD : Get or Set MQTT password

AT+PUBTOPIC : Get or Set MQTT publish topic

AT+SUBTOPIC : Get or Set MQTT subscription topic

Information

AT+FDR : Factory Data Reset

AT+PWORD : Serial Access Password

AT+LDATA : Get the last upload data

AT+CDP : Read or Clear cached data

4. Battery & Power Consumption

PS-KN use Charging Pad + 1000mAh Li-ion Battery pack. See below link for detail information about the battery info and how to replace.

Battery Info & Power Consumption Analyze .

5. Firmware update

User can change device firmware to:

• Update with new features.

• Fix bugs.

Firmware and changelog can be downloaded from : Firmware download link

Methods to Update Firmware:

• (Recommended way) OTA firmware update via BLE: Instruction.

• Update through UART TTL interface : Instruction.

6. FAQ

6.1 How can I access t EG800-NGFF AT Commands?

User can access to EG800-NGFF directly and send AT Commands.

See EG800-NGFF AT Command set

6.2 Why is there no LED response when I press the button on the solar panel model?

If the LED does not light up when you press the button, it may be because the battery has entered protection mode.

Solution: To reactivate the battery, simply expose the solar panel to direct sunlight. For more details, please refer to: Battery Protection State (Apply to Solar Panel + Li-ion battery)

7. Order Info

Part Number: PS-KN-XX-YY

XX:

• GE: General version ( Exclude SIM card)

• 1T: with 1NCE * 10 years 500MB SIM card and Pre-configure to ThingsEye server

YY: The grand connector hole size

• M12: M12 hole

• M16: M16 hole

• M20: M20 hole

8. Packing Info

Package Includes:

• PS-KN NB-IoT Analog Sensor x 1

• External antenna x 1

Dimension and weight:

Package Size / pcs :

• For PS-KN: mm
• For PS-KS: mm

Weight / pcs :

• For PS-KN: g
• For PS-KS: g

9. Support

• Support is provided Monday to Friday, from 09:00 to 18:00 GMT+8. Due to different timezones we cannot offer live support. However, your questions will be answered as soon as possible in the before-mentioned schedule.

• Provide as much information as possible regarding your enquiry (product models, accurately describe your problem and steps to replicate it etc) and send a mail to support@dragino.com.