Define the Maximum Message Length Properties for a Pager Service

Every pager and mobile telephone has a maximum number of characters that it can receive in a single message. As this limit can vary between devices, you need to include the limit supported by your devices in the Pager Service configuration. This allows Geo SCADA Expert to determine whether a message is going to exceed the message size supported by the recipient mobile telephone or pager.

If Geo SCADA Expert needs to send a message that does exceed the limit that is supported by the recipient pager or mobile telephone, Geo SCADA Expert will attempt to shorten the message. You can use the Pager Service configuration to choose the method of message shortening that Geo SCADA Expert will use.

To define the maximum message length and the action to be taken if the message length is exceeded:

1. Display the Pager Service Form.
2. Select the <Pager> Service tab, for example, for a Multitone Pager Service, select the Multitone Service tab.
3. Define the Maximum Message Length. This has to match the maximum message length that is supported by the recipient mobile telephone or pager. For more details, please refer to the documentation supplied with your pager or mobile telephone.

   The Maximum Message Length should be long enough to contain plain text message and any parameter substitutions that are included as a result of using trip characters. Trip characters are only relevant to alarm messages that are redirected automatically (see Trip Sequences Supported by Redirection Actions in the Geo SCADA Expert Guide to Alarm Redirection).

   For UCP Pager Services, the highest amount you can enter for the Maximum Message Length is dependent on whether the Service Provider is set to use Long Messages. If it is set to use Long Messages, the Maximum Message Length can be up to 640. If Long Messages are not used, the Maximum Message Length can be up to 160.

4. Use the When Message Length Exceeded property to specify which message shortening method Geo SCADA Expert will use to reduce the size of any messages that exceed the Maximum Message Length.

   Choose from:

   • De-Vowel—If a message exceeds the Maximum Message Length, Geo SCADA Expert attempts to shorten the message. First it removes duplicate spaces, then if the message is still too large, it will remove duplicate letters (one letter at a time until the message fits). If the message is still too large, Geo SCADA Expert will remove the vowels one letter at a time, starting with the first word in the message. If the vowels are removed and the message still exceeds this length, the message is then truncated (see the Truncate option, below).
   • Truncate—If a message exceeds the Maximum Message Length, those characters that appear after the limit are omitted. For example, if the Maximum Message Length is 160 and a message contains 168 characters, the characters from 161 to 168 inclusive will be removed from the message before the pager driver sends it to the relevant pager or mobile telephone.

     If you choose the Truncation option, engineers will need to include the crucial part of any message within the Maximum Message Length.

5. Save the configuration (see Saving Configuration Changes in the Geo SCADA Expert Guide to Core Configuration).