Application Case

Haiwell solution for the wireless communication of the table printing machine

2021-06-28 09:40:36 Xiamen Haiwell Technology Co., Ltd. Read

Author: Project dept.

The document mainly introduces the wireless communication solution of the table printing machine. In the past, PLC and touch screen communicate mostly with each other via wireless DTU (Data Transfer Unit). However, it needs once the device communication forwarding via DTU, this greatly increases the communication time. In this solution, the direct communication between devices can easily realize by using the Haiwell HMI with WIFI, which successfully replaces the original communication model - DTU, so as to reduce device cost and communication time, and improve the work efficiency. In the meantime, the Haiwell HMI supports remote access via mobile phone APP and website, which can conveniently view the status of the running device and production, supports WeChat alarm and timely detection of abnormal equipment, supports remote uploading and downloading of HMI and PLC, convenient for engineer remotely maintain devices.

I. The action logic analysis of the Haiwell table printing machine

The table printing machine is composed of the printing car, connecting car and the plurality groups of guide rail.

The printing car runs on the guide rail and it prints according to the limit switch. When the car on the rail printed completely, it’ll send the connecting signal to the connecting car. After the connecting car reached the specific position, it sent the forward instruction to the printing car. After waiting the printing car to move to the connecting car, the connecting car start to move it to the next guide rail platform. After reaching the next platform, it will receive the forward printing signal.

Due to the length of the guide rail platform is not fixed, the printing car and connecting car only connected via wireless connection. The original solution is to send the PLC signal of the car to the wireless module, then the signal from the wireless module is sent to the wireless module of the car, finally the signal from the wireless module of car is sent to the PLC of car. So that sometimes it will be communication interruption or busy, resulting in the printing car or the connecting car does not move or action delay.


Table printing machine

Base on the above problems, Haiwell provided customer a way of the wireless TCP connection via the Haiwell HMI with WIFI to delete the use of the wireless module, so as that to solve the problem of the multiple forwarding connection, and it's easier to maintain.

II. Analysis of the short distance wireless communication of Haiwell HMI 

Short distance communication can be realized by Haiwell HMI with WIFI. When Haiwell HMI communicates via WIFI, can be as the master and slave device at the same time. So as that, we simply incorporate the HMI that need to communicate into the LAN and use MODBUS TCP via WIFI to communicate. The following will briefly introduce the operation steps of Haiwell HMI on the software:

1.Set up the slave device: Open the project, click the device in the project browser on the left side, press F12 and slave device will appear,then add a MODBUS slave (TCP).


Set up the slave device

2.Set up the slave address variable, the variable from the slave device can be read directly by HMI as the slave address. As the ModBus slave device, the slave address is custom, so that it's more convenient to use when the slave device ModBus address has been planned for the large system.


 Set up the address variable of the slave station

3.Create the master device 


 Set up the master device

4.Set up the address which can read the variable of the slave device 


 Set the variable of the slave station

If the master and slave HMI is connected in the same LAN, the communication will be successful, and the coverage range can be extended through the bridge mode of the AP router.

III. Project screenshot and running video

1. Printing car


The monitoring interface of the printing car


The setting of the slave station address of the printing car

2.Connecting car



The setting of the slave station address of the connecting car

3.Equipment operation video

IV. Remotely monitoring the Haiwell table printing machine

Haiwell IoT cloud HMI = common HMI + IoT gateway + DTU. Haiwell C7S-W HMI is selected in this solution, which supports Internet via LAN and WIFI, as long as connect to the network in the original LAN, then remotely monitor and update the project of HMI and PLC, convenient for remotely debug. Build-in the MQTT protocol, providing the software and hardware support for centralized monitoring of data and connect to the database and factory MES system. 


The picture of the remote accessing