Echelon i.LON 100 e2 Internet Server - Manual (Page 20)

2-6 Mounting, Cabling and Connections
• High voltage mains power;
• Dry contact relay outputs;
• Pulse meter inputs;
• Digital inputs;
• L
ON W ORKS network;
• +12V < 20mA Output;
Each of these groups is described in detail below.
RS-232/RS-485 Serial Ports
The i.LON 100 includes one isolated RS-485 multi-drop bus port and one EIA-232
serial port. These ports can be used to connect the i.LON 100 to a GSM modem,
to other computers, or to bus systems. To connect the i.LON 100 to a GSM
modem, the serial connector from the modem must be attached to the ports on
the i.LON 100 as shown in the following table:
i.LON 100 Server GSM Modem Connections
GSM Modem DB
9 Pin
i.LON 100 Screw
Terminal
Enclosure Marking
1 not connected N/A
2 pin 23 RXD
3 pin 24 TXD
4 not connected N/A
5 pin 25 GND
6 not connected N/A
7 pin 21 RTS
8 pin 22 CTS
9 not connected N/A
If the RS-485 and EIA-232 ports are physically connected to a device other than a
GSM modem or an M-Bus device, a special custom software driver must be
provided by Echelon to support the intended application and enable
communications over the port (check the Echelon website (www.echelon.com) for
availability).
The EIA-232 serial connections are implemented on screw terminals 21 through
25. To connect a GSM modem to the i.LON 100 RS-232 port, a cable may be
ordered in Europe from EBV. The part number is ECH-RS232/500.
The RS-485 bus connections are implemented on screw terminals 26 though 28.
These are polarity sensitive signals and the (+) and (-) connections are noted
adjacent to the terminals. Since RS-485 is susceptible to common mode ground
differential voltage swings, it is imperative that a suitable shielded cable be used
when connecting RS-485 based devices. Reversing the polarity of the RS-485 bus
will cause improper bus operation and must be avoided.
In order to connect M-Bus devices to an i.LON 100 device, a level converter is
needed. This level converter is connected to the RS-232 interface of the i.LON
100 and to the M-Bus devices. It not only converts the M-Bus signals to RS-232