4. PBX Systems
Note the following:
• The string buffer used to pass the parameter cannot be more than seven
characters plus the NULL terminator.
• If the feature access code is set in this way, the application can do the
MWI operation using <ESCO> or <ESCF> strings.
MWI On
A technique to turn on the MWI in this switch, using dx_dial( ) with the dial
string, is to:
1. Go off-hook using the dx_sethook( ) function.
2. Call the dx_dial( ) function. The dial string is
<ESCO>,<extension>,<ESCO>.
3. Go on-hook using the dx_sethook( ) function again.
NOTE: <ESCO> means the Escape character followed by O.
MWI Off
A technique to turn off the MWI in this switch, using dx_dial( ) with the dial
string, is to:
1. Go off-hook using the dx_sethook( ) function.
2. Call the dx_dial( ) function. The dial string is
<ESCF>,<extension>,<ESCF>.
3. Go on-hook using the dx_sethook( ) function again.
NOTE: <ESCF> means the Escape character followed by F.
You can use the pause character (comma) in the dial string for MWI
manipulation to avoid unpredictable results under load.
Reading the State of the PBX Integration Board MWI Indicator
The Dialogic® PBX Integration Board can determine the state of its own
Message Waiting Indicator using the d42_indicators( ) function to read the
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