3COM 3C886A-US 56K LAN Modem The following is a guideline for remote connectivity to an Ethernet network via a phone line. It uses a 3COM LAN Modem (p/n 3C886a) as a modem, gateway, router and hub. It was tested using the configuration shown below. The ViewStation was communicating with the 9030 through the LAN Modem. The PC on the remote system could browse the ViewStation s web server as well as program the PLC. This PC is optional and could be used to tutor or communicate with a technician at the remote site. Using the LAN Modem, the other PC could dial into the network and communicate with the PLC to go online and make changes, browse the ViewStation to see status, download a new program to the ViewStation, and even link to the remote PC using NetMeeting. It acts just like the PC on the remote system only slower since it s through the phone line. Created by Kevin Dowell Page 1 of 6 GE Fanuc Automation
To set this system up you must first, establish communications with the LAN Modem. The default address is 192.168.1.1. Use your browser to bring up the LAN Modem configuration menu. You will be given an opportunity to set up a system password. In a final installation where security is an issue you will want to use this feature. Once you are talking to the LanModem you need to set some parameters. Created by Kevin Dowell Page 2 of 6 GE Fanuc Automation
1. LAN Parameters: The LAN Modem must have an IP address. The default is 192.168.1.1. You can change it if you like. Make the subnet 255.255.255.0 and enable DHCP. Created by Kevin Dowell Page 3 of 6 GE Fanuc Automation
2. Workstation configuration: Setup up the table to reserve the static IP addresses of the devices on the remote network. This will ensure the DHCP server does not duplicate an IP address that is used by a static device. The devices should be on the same network as the LAN Modem. (First three numbers of the IP address match) Note that you can assign up to 25 devices on the network. The LAN Modem only has 4 ports. Additional hubs can be added to route to the additional devices. Note: The LanModem is a 3COM OfficeConnect product. It designed for an office environment that has a network of workstations thus the name. In our application, the workstations are our devices on the remote network. Created by Kevin Dowell Page 4 of 6 GE Fanuc Automation
3. Dial-in user Set up an account for a dial-in user. Dial-in users CANNOT use the ADMIN account. The ADMIN account will not allow the remote user to connect to the network. The only fields required are the Name, Password and IP and Subnet Mask. Give the dial-in user an address that IS NOT on the network. (Example: 192.168.2.253) Use 255.255.255.0 as the Subnet Mask. The LAN Modem will assign this address to the dial-in user and will allow the dial-in user access to the network. Created by Kevin Dowell Page 5 of 6 GE Fanuc Automation
You do not need to set up Data Call Parameters or Service Providers as they are not used in this configuration. 4. Devices in remote location (CE boxes and PLCs) Assign static IP addresses to the devices that match those in the workstation configuration table. Give STATIC IP addresses that are on the same network as the LAN Modem. (First three numbers of the IP address match) Assign a subnet of 255.255.255.0 and, if available, assign the gateway address that matched the address of the LAN Modem. 5. Dial-in PC configuration Use dial-up networking to set up an account. When dialing you will be prompted for a username, password and domain. Enter the Username and Password you set-up in the dial-in user section above. Leave the domain blank. If you experience problems, try these two fixes: 1. Make sure the domain field in dial-up networking is BLANK. Sometimes a space character can lurk in this field and not allow a connection. 2. Make sure the IP addresses of other Ethernet devices on the dialing PC (i.e. NIC cards) are on different networks than the LAN Modem. If the are on the same network, you will connect to the LAN Modem but when you open the browser and enter the LAN Modem s IP address, your PC will try to find it via the NIC instead of dial-up networking. Created by Kevin Dowell Page 6 of 6 GE Fanuc Automation