Download 3COM 3C886A

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.
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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.
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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.
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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.
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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.
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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.
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GE Fanuc Automation