Use Ethernet or Dialup

The RTU can connect to an Ethernet network where this is available, or you can use dialup to connect using leased line or a phone network.  The RTU can also send SMS messages over a mobile network.

Communication Methods

The RTU has flexible modes of communication.  The options are:

Ethernet link

serial leased line

dialup using the PSTN (telephone system) network

dialup using the GSM (mobile phone) network

dialup using the CDMA (mobile phone) network

SMS (mobile text) messages using either the GSM or CDMA networks

If Ethernet is the primary mode of communication, and a suitable modem is attached to the RTU's serial port, the RTU can be configured to automatically fall back to serial communication if it detects a failure in the Ethernet link.

Ethernet Link

The easiest and quickest way to connect an RTU to your network is by using an Ethernet link.  The RTU will connect to a 10/100BaseT network.

Use the front panel to quickly and easily set the IP address of an RTU.

Once the RTU is plugged into your network, you will be able to observe the Link and Activity lights at the back of the unit.  The run-time information area of the front panel menu will display the actual IP address at which the RTU is connected.  If there is no connection, this will be blank.

The HTTP, SNMP, SMTP and NTP protocols are supported over the Ethernet link.  Data and commands are sent and received rapidly over this type of connection.

Dialup

The RTU is equipped with a serial port to which you can attach a modem (not supplied).  The modem can be:

serial leased line

PSTN (public switched telephone network)

GSM (mobile network)

CDMA (mobile network)

If an Ethernet link is available, you can use the serial port as a failover.  This means that if the RTU detects a problem with the Ethernet link, it will switch to the modem to get its notifications out.

If there is no Ethernet link available, the modem can be used as the primary means of communication.  Unless you are using SMS (see below) you will need to configure the RTU, and a suitable host computer at your Operations Centre, to establish a PPP (Point to Point) connection.

PPP allows IP protocols to operate over a serial link.  This means that once communication has been established, an IP connection is negotiated between the RTU and the host network.  Once this is complete, communications with the RTU can proceed in exactly the same way as it would over an Ethernet connection, except it is slower.  The RTU sends out settings and status information as small XML documents, and the system runs well even on a slow 9600 baud mobile network.

The benefit of using this approach is that you can mix Ethernet-connected RTUs with dialup-connected RTUs, and they all operate the same way.  The PPP connection supports all the protocols used by the RTU over an Ethernet connection.

SMS (Short Message Service, Mobile Text)

If you have a mobile network modem attached to the RTU, you can also use SMS as a means of getting notifications out to staff.  This functionality can be used in conjunction with Ethernet and / or dialup connections, or it can be the sole means of notifications.

Please note that SMS messages are generally not guaranteed to be delivered in a timely manner, or at all.  Check with your mobile service provider before using the SMS service for sending out notifications.  Note also that the RTU only sends out SMS messages, it does not receive or process them coming in.

You can configure up to two phone number destinations to which the RTU will send notifications.  When a notification needs to be sent, the RTU will send the message to all the numbers that have been configured.

The SMS message that is sent is a summary message.  It identifies the RTU and shows the number of ports that are in alarm and historic states.  It also names as many of these ports as possible in the allowed space for an SMS message.