This COM over IP software gives you a way to create a virtual serial port on your local computer and then link it to a real COM interface of a remote CNC machine. By using this network connection, you can load programs and data to remote CNC machine tools.
1.1. Access CNC machines remotely over Telnet
Let’s imagine there’s a CNC machine supporting Telnet (RFC 2217) communications. You need to send some data to it from a specialized application running on your home computer. To achieve this, you install RS232 to IP software on your PC and establish a client connection to the remote CNC equipment.
Once the connection is created, you are able to “talk” to the remote machine as though it were attached directly to your computer’s serial port. What’s especially convenient is that there’s no need to install serial to TCP/IP converter software on the remote end.
If you are working with a time-sensitive app, you can select the UDP/IP protocol and forward your serial data over a local network. Or choose the RAW data transmission algorithm and the data will be sent “as is”, without any additional protocol-specific formatting.
1.2. Share CNC machine tools with multiple users
Now, let’s see how to share access to your manufacturing equipment among multiple network users.
First, you should connect the required CNC machine to a serial port of your PC. Then, install Serial to TCP/IP Connector software. This app will help you turn the PC into a COM over IP server. Once done, start the program on your computer and share the serial port over the IP network. After being shared, the port with the device attached becomes available for connections from remote client computers.
1.3. Redirect serial ports to a virtual environment
With a reliable serial port over IP redirector app, CNC machine operators get the ability to edit programs, check cut progression or troubleshoot from any PC - be it a host computer or a guest OS.
In order to connect to a serial device over your IP network, first of all, you need to share the host’s COM port to which the equipment is attached. Eltima’s RS232 over IP Connector will let you do this with a couple of clicks.
Once the host’s serial port is shared, create a virtual copy of this port in your guest OS.
Next, specify a TCP port to connect to and the IP address of your host computer and establish a client connection to the shared serial port from your virtual machine.
This is it! Now you can access the virtual port from your CNC app and the dedicated software RS232 over IP connector will redirect the input/output data from this program directly to a CNC machine over a serial connection over IP.
2. How to share a CNC COM port over IP - software and hardware tools
Fabrication with CNC machines brings many challenges. It often happens that you need to work from an office quite separated from the factory floor. In this case, sharing your serial equipment over the IP network is probably the best option. Remote access to COM over IP means you can run your CNC machine from any device on your LAN or Wi-Fi network.
So, let’s have a look at the most common ways to share a serial device over IP.
2.1. Manage a CNC machine over Wi-Fi with Raspberry Pi
The first method allows you to transfer data between a CNC machine and the computer which is controlling it over Wi-Fi. What makes it possible is the GRBLWeb software running in your browser. The program lets you control your GRBL board over Wi-Fi with the help of a Raspberry Pi.
To complete this task, you’ll need:
A CNC router running GRBL 0.8, a Raspberry Pi board, a Wi-Fi dongle, a USB A-B cable, an SD card, a 5VDC USB Power Supply, a USB A-Micro B cable, an Ethernet cable, a Wi-Fi router with DHCP enabled and at least one free Ethernet port.
The software components:
SDFormatter, Win32DiskImager, WinZip or any other unzipping utility, and PuTTY SSH client.
Once everything is ready, just follow these steps:
- Download the Raspberry Pi Image file with the GRBLWeb software at http://xyzbots.com/grblweb.html
- Use the SDFormatter program to format your SD card in order to make it work with the Raspberry Pi.
- Move the Raspberry Pi Image to your SD card with the help of Win32DiskImager.
- Insert the SD card into the Raspberry Pi. Attach the Raspberry Pi to your router via an Ethernet cable and connect a 5V micro USB power supply to the Raspberry Pi.
- LEDs on the board should indicate that the boot process has started.
- Now, get an IP address for your Raspberry Pi. The IP address will be assigned to your Pi by the router using DHCP.
- Log in to the Raspberry Pi. To do this, in PuTTY SSH client, enter the IP address of your Pi, choose SSH and click Open. In a terminal window that will appear, enter your default login credentials "pi" and "raspbian".
- Next, you should open the configuration menu for the Pi and change the password. Also, select your language and timezone in the "Internationalisation Options."
- Now, it’s time to set up Wi-Fi. At this stage, you should modify the instructions in a configuration file so that they meet your needs. It’s recommended that you set up the Raspberry Pi to have a static IP address.
- Once the Wi-Fi configuration is complete, link the GRBL board to the second USB port on your Raspberry Pi via a USB A-B cable. Start your CNC machine.
- Launch the GRBLWeb software in your browser and check the status of your CNC machine by typing http:// + [your Pi's IP address] and pressing Enter. Then, find the Arduino running GRBL in the drop-down menu of the app.
- Finally, try controlling the movements of your machine from the program.
It’s also worth mentioning that remote access to a CNC machine is not always the safest option. It is rather uncommon to make the whole process automatic without human action. Your device may miss some steps or lose a bit, so there should be either an operator supervising the process or a reliable monitoring system. You should also keep in mind that to make things work properly, you’ll need to spend some time learning the GRBLWeb program.