Guide to Communication between PC and INVT IVC1 PLC over Internet

1. Introduction:

With the remarkable development of Internet, monitoring, programming, and troubleshooting systems over Internet provide numerous benefits to users. In this guide, we will introduce steps to establish communication between HMI and INVT IVC Series PLC over Internet.

2. Required Equipment and Software:

– Autostation: Programming software for IVC1/IVC2 – xxx.
– INVT IVCS-EPM Module: This module converts Modbus RTU to Modbus TCP/IP.
– INVT HMI VTxxx-H1ET with integrated Ethernet port 10/100Mb.
– VT Designer: Programming software for INVT HMI.
– Internet network cable, Router, and an ADSL connection.
– Net-Config software, used for configuring IP address of IVCS-EPM Module.

3. Steps to Follow:

Step 1: Connect PLC IVC1/IVC2-xxx to IVCS-EPM Module using a noise-resistant cable, and connect IVCS-EPM Module and INVT HMI to Router using network cables.


Step 2: Use Net-Config software to configure IP address for IVCS-EPM Module and select the working mode of  IVCS-EPM Module as Modbus TCP/IP slave, as shown below. Additionally, IVCS-EPM Module can operate with RS232 or RS485 standards, depending on the selection. Refer to IVCS-EPM Module Manual for detailed configuration steps.


At this point, PLC communication standard is Modbus TCP/IP, and default network port for PLC is Port 502.

Step 3: Power up the HMI, go to the “General” tab, and configure the IP address, Subnet mask, and Default gateway for the HMI.


Note: The IP addresses of HMI, PLC (IVCS-EPM Module), and other components (PC/Laptop) in network must not conflict with each other. The Subnet mask and Default Gateway addresses for all components in network must match. For Default Gateway, refer to your network provider (ISP).

Step 4: On PC/Laptop, use a network cable to connect to Router. Then configure IP for PC/Laptop. (This step can be skipped as Router can automatically assign IP addresses to PC/Laptop).

Step 5: On PC/Laptop, ping IP address of IVCS-EPM Module and HMI. If successful, it means PLC IVC1/IVC2-xxx and HMI are connected; if unsuccessful, repeat Step 2.


Step 6: On PC/Laptop, open Autostation software, select the “System block” tab, go to “Communication port,” and configure Port 1, communication port with HMI, as follows:


Communication parameters such as Baud rate, Parity check, Data bit, Stop bit, etc., must match the configuration of IVCS-EPM Module.

Next, write a simple program for PLC to communicate with HMI. Note that all PLC addresses such as M0, X0, Y0, D0, etc., must be mapped to Modbus addresses. Refer to IVC Series Manual, Appendix 7, for more details.

Step 7: Open VT Designer software to program HMI. Configure and write a simple program as follows:

In “Project Manager” tab, select “Link 1,” and “Link Properties” window will appear. Go to “General” tab and configure as follows:


Next, select “Parameter” tab and configure as follows:


Since the working port on PLC’s network system is Port 502, configure communication between PLC and HMI through Port 502.

Write a simple program to monitor PLC through Modbus TCP/IP standard.

Now, PLC and HMI can communicate with each other over LAN (Local Area Network) using Modbus TCP/IP.

Step 8: To connect PLC IVC1/IVC2-xxx to HMI over WAN (Wide Area Network), connect HMI to an ISP’s ADSL/Wifi connection. First, check IP address of network where PLC is connected; this is address provided by ISP through websites such as http://ipaddress.com or http://www.whatismyip.com.

Next, open Port 502 of PLC IVC1/IVC2-xxx (IVCS-EPM Module) IP address on ADSL Router. This Port opening process depends on Router type and network provider.

Then, in VT Designer software, reconfigure communication IP address with PLC as follows:

Note that communication IP address with PLC in VT Designer configuration should now be IP provided by ISP.

Step 9: From here, you can control and monitor PLC IVC1/IVC2-xxx through HMI from anywhere with an Internet connection.

Note: You must regularly update PLC’s IP address because IP provided by ISP is dynamic and changes constantly. This update can be done through software or manually.

In addition, users can use VNC Server software to access and control HMI over Internet. VNC is an independent server that users can download from Internet, and it supports operating systems like Windows, iOS, and Android. With VNC Server, users can connect directly to HMI through Internet using PCs, laptops, smartphones, tablets, etc.