USER GUIDE FOR WIRELESS AMBIENT OXYGEN SENSOR WS433-O2

This document is applied for the following products

1. Functions Change Log

2. Introduction

WS433-O2 is the Wireless Ambient Oxygen Sensor, it utilises galvanic cell type oxygen sensor which provides a linear output voltage signal relative to percent oxygen present in a particular atmosphere. The sensor features no position dependency, excellent chemical durability, and it is not influenced by CO. The wireless portion is Sub-GHz technology from Texas Instruments allows long range transmission at ultra-low power consumption. It will connect 2-way wirelessly to the wireless co-ordinator WS433-CL to send data and receiving the configuration. It can be configured the operation parameters like data sending interval, health check cycle...remotely from Globiots platform or via ModbusRTU software (thru the WS433-CL). Its default data rate is 50 kbps, can be switched to 625 bps cato increase the communication range. It can last up to 10 years with a single AA battery. There are a lot of applications as environment monitoring for office, hospital, cleanroom...

3. Specification

4. Typical Applications

5. Operation Principle

5.1 Process of measurement

When the sensor sampling time interval is reached, For example 2 minutes, the node will wake up and switch ON the power supply to supply the energy to external sensor to start the measurement. Depends on the type and characteristic of external sensor, the sensor will take a certain time to finish the measurement.

For example: the measurement time is 200mS, after this time, the node will read the value of sensor, node will switch OFF power supply to external sensor to save energy.

The measured value is the raw value of the sensor. The measured value can be scaled according to the following formula:

Y = aX + b

• • • • • X: the raw value from the sensor
        • Y: the calculated value for parameter 1's value or parameter 2's value
        • a: constant (default value is 1)
        • b: constant (default value is 0)

So, if there is no user setting for a and b ==> Y = X

The Y value will be compared with Lo and Hi threshold. Please refer below the graph of alarm processing.

Status bytes of sensor Node

• Hi-Byte is error code

• Lo-Byte is sensor type

5.2 Add sensors node to Co-ordinator WS433-CL

5.2.1 Add Sensor Node ID automatically

Step 1: After supplying power the Co-ordinator via M12 connector, the Node ID must be registered within the first 5 minutes, up to 40 WS.

Step 2: Bring the wireless sensor closer to the Co-ordinator's antenna then take off the wireless sensor battery, wait for 5s then insert the battery again. If:

• Buzzer plays 1 peep sound, LED blink 1 time, that means registering Node ID on Co-ordinator successfully.
• Buzzer plays 2 peep sounds, LED blink 2 times, that this Node ID is already registered.

If you do not hear the "Peep" sound, please disconnect the power the co-ordinator, wait a few minute and try again.

Node id added in this way will be written to the smallest node_id_n address which is = 0.

Set Rssi_threshold (see RF MODE CONFIG (in the Modbus Memmap of WS433-CL), default -25): The case if Co-ordinator is on high position and need to add node sensor. We set the sensor as close as possible and set the Rssi_threshold to -80, -90 or -100 to increase the sensitivity to allow WS433-CL-04 can add sensors at a longer distance. After that, perform 2 steps of adding sensors and then reset Rssi_threshold = -25.

Enb_auto_add_sensors configuration (see RF MODE CONFIG (in the Modbus Memmap of WS433-CL)): In case you do not want to turn off the power WS433-CL, you can set Enb_auto_add_sensors = 1, this way we have 5 minutes to add nodes (add up to 40 nodes) . After 5 minutes Enb_auto_add_sensors will automatically = 0.

Memmap resgisters

You can download Modbus Memmap of WS433-CL with the following link:

https://filerun.daviteq.com/wl/?id=WBbGm89AToHWyvIyMOc780N1KmjfUr3Y 

5.2.2 Add sensor node into WS433-CL-04 (1) through intermediate WS433-CL-04 (2) and Modbus

In case the sensor need to be added to WS433-CL-04 (1) has been installed in a high position, the sensor cannot be brought close to WS433-CL-04 (1). For more details:

http://www.daviteq.com/en/manuals/books/long-range-wireless-co-ordinator-ws433-cl/page/user-guide-for-long-range-wireless-co-ordinator-ws433-cl

5.3 Button Function

Open the cover of sensor then use the push button to set the data transfer speed for the first 30 seconds when the battery is first installed, after 30 seconds the push button function does not work.

• Press and hold the button for 2 seconds => LED blinks once => Release the button to set Data rate RF 50kbps
• Press and hold the button for 5 seconds => LED blinks twice => Release the button to set Data rate RF 625bps
• Press and hold the button for 10 seconds => LED blinks 3 times => Release the button to reset RF parameters (frequency, RF output power, data rate), if held for more than 30 seconds then the button function does not work.

Reset default WS433:

Frequency: 433.92 MHz
RF transmit power: 15 dBm
RF data rate: 50 kbps

5.4 Configuration

First, you need to prepare

Num of Node will indicate the number of nodes managed by WS433-CL.
Every time a node is added, the Num of Node will increase by 1.
Every time a node is deleted, the Num of Node is reduced by 1.
Writing Num of Node = 0 will delete all 40 node ids to 0.
If you want to delete a node id, then write it = 0 with the Write function is 16 and the Read function is 3.

Step 1: Connect Antenna, RS485 - configuration cable and power supply co-ordinator

Step 2: Open Modbus tool on PC

• You can download Daviteq Modbus Configuration Tool with the following link:

https://filerun.daviteq.com/wl/?id=qK0PGNbY1g1fuxTqbFW9SXtEvCw7bpc6

Template File: https://filerun.daviteq.com/wl/?id=ItFaeQgtCmXN98J7GaPdeZvKK5eS1Dd1 

How to use the Modbus configuration software 

• Unzip file and run file application "Daviteq Modbus Configuration Tool Version"

• Choose COM Port (the Port which is USB cable plugged in)
• Set the BaudRate: 9600, Parity: none

• Click “ Connect “ untill the Status displays “disconnected” to “connected“. It means the WS433-CL-04 is being connected with computer;
• Next, we need to import the configuration file for WS433-CL-04 by importing the csv file: Go to MENU: FILE / Import New / => select the template file.

Step 3: Configure parameters of the sensor.

Memmap resgisters

You can download Modbus Memmap of WS433-CL with the following link:

https://filerun.daviteq.com/wl/?id=BKEaUzdArkoc0Hc7nfpRShdPVToVrqQZ 

In the memmap file, refer to the Memmap of WS433-AI sheet to configure the sensor's operating parameters accordingly.

The reference memmap addresses are based on the order of the sensors added in the Memmap file above

Typical sensor parameters:

6. Installation

6.1 Installation location

Wireless sensor utilize the ultra-low power 433Mhz RF signal to transmit/receive data with Wireless co-ordinator.

To maximize the distance of transmission, the ideal condition is Line-of-sight (LOS) between the Wireless sensor and Gateway. In real life, there may be no LOS condition. However, the two modules still communicate each other, but the distance will be reduced significantly.

ATTENTION:

DO NOT cover the Wireless sensor or its antenna inside a completed metallic box or housing, because the RF signal can not pass through the metallic material.

NOTE:

Integrated WS433-CL / iConnector Coordinator The coordinator must be placed at least 4 meters above the ground and the WS433-O2 clearly visible.

6.2 First setup

Please follow the steps described below

Step 1: Open the cover of the sensor

Step 2: Remove the tape on the sensor's filter

DO NOT TOUCH WITH YOUR HANDS OR CONTAMINATING THE SENSOR FILTER

Step 3: Carefully reattach the sensor protective cover

Now the sensor is ready to use

6.3 Dimensions

Unit: mm

6.4 Battery installation

Steps for battery installation:

Step 1: Using Philips screw driver to unscrew M2 screw at the side of housing.

Step 2: Pull out the cover then insert the AA 1.5VDC battery, please take note the poles of the battery.

ATTENTION:

Because of O-ring, it requires to have much pulling force at the beginning, therefore please do it carefully to avoid the damage of circuit board which is very thin (1.00mm);

REVERSED POLARITY OF BATTERIES IN 10 SECONDS CAN DAMAGE THE SENSOR CIRCUIT !

Step 3: Insert the top plastic housing and locking by M2 screw

7. Troubleshooting

8. Support contacts