User's Manual

GridRouter™ User Guide
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7.2 Serial Data Concentrator to NES
When a serial Echelon Data Concentrator (DC) is connected directly to a modem it dials a number with an
AT command (i.e. “ATDT10001”). The modem will respond with “CONNECT” and then the Point-to-Point
Protocol (PPP) will be used to establish a direct connection between the DC and the Internet service
provider (ISP). The GridRouter acts as a modem emulator and will listen for the “ATDT” command before
responding with “CONNECT” and then initiating the PPP connection.
The DC will natively try and alert the head-end server (NES) whenever its IP address changes. Since the
DC is on the GridRouter’s local network (192.168.*.*), the DC’s IP address will normally stay the same, so
that the firewall rules can be the same. Therefore, the DC will never alert the NES server when the WAN
address of the GridRouter changes, leaving the DC without communication.
The GridRouter has the ability to change the local IP address of the DC when the WAN address changes
to force the DC to alert NES. A primary and a secondary IP address are toggled and assigned to the DC
and the firewall rules are automatically altered to match the DC’s address. To ensure that this toggling of
addresses is used on the DC, make sure to enable the ‘Update Local IP’ rule on the web interface.
The steps required to set up the GridRouter to connect to a Data Concentrator are as follows:
1. Attach a null modem serial cable between the Data Concentrator and a GridRouter serial port.
2. Visit the web-based utility’s Network > Serial PPP screen.
3. Click the Enable button on an instance of the serppp process.
4. Enter the correct serial port settings.
5. Enter both a primary and secondary local IP address to assign to the Data Concentrator.
6. Disable ‘Update Local IP’ if your GridRouter has a static IP address.
7. Add port forwarding rules so that the NES software can reach the Data Concentrator through the
GridRouter’s firewall.
Figure 7-1: Example Port Forwarding Rules for a DC
8. Click Save Changes. Wait for page refresh.
9. Verify configuration values.
10. Click Apply Changes & Reboot.
Once the GridRouter reboots, the serppp process will be running and the Data Concentrator will be ready
to go.
Note: Common communication ports for the Echelon Data Concentrator are 65432, 65400, and 22 (SSH).