MPC Data Protocol
From Zenitel Wiki
The AlphaCom supports a subset of the MPC data protocol used with the classic Stentofon TouchLine exchanges. As it allows control of the AlphaCom exchange by mapping MPC commands to AlphaCom commands one-to-one it can be thought of as a variant of the simple link layer, but only for single-exchange (not AlphaNet) applications.
The output is broadcast of exchange events like dialled digits, station busy/free, connection and transfers. Note that it’s possible to send additional data strings from the AlphaCom’s Event Handler on this port also.
The AlphaCom supports a subset of the MPC Data Protocol for backward compatibility. This allowed some TouchLine generation equipment like PNCI, MLH and CRM to be used with the AlphaCom.
Contents
Availability
AlphaCom has supported a serial data port which outputs TouchLine formatted output messages since AMC 03.00. From software AMC 07.60, a limited subset of TouchLine input commands are supported also.
Disclaimer
The TouchLine input commands have been implemented by translating them to existing AlphaCom data protocol commands. This means that the commands may not behave 100% identical compared to a TouchLine exchange in all possible situations. You should think of it as a simple ASCII link layer protocol to AlphaCom functionality.
Tips for use
Many AlphaCom features require additional parameters, which can not be supplied when using TouchLine message format. A possible workaround is to use the Event Handling, where you can set up action commands with many parameters.
- Create a directory number bbbb with feature 85, "Event trigger"
- In the Event Handler, add an "Event Trigger Feature" event on station aaaa.
This occurs when bbbb is dialed on station aaaa.
- Configure the desired action commands for the event. The action can be as complex as you like.
Now you can use the “H aaaa bbbb” TouchLine command to execute the configured action.
The TouchLine Protocol
Some internal events in the AlphaCom system are reported on an output data channel. The events are as lose to similar events in the TouchLine system as possible. The data protocol format used are TouchLine compatible. The aim for the chosen subset of the protocol was to support specific existing external equipment using only the output data from the TouchLine Exchange, such as PNCI, MLH and CRM external equipment.
Data Port
The physical data port where the TouchLine compatible data appears is programmable using AlphaPro. (The default port is Port 1). The data port is an EISA RS232C compatible interface. The format for data transmission is programmable. The default format is:
- 9600 baud
- 7 bits ASCII characters
- even parity
- 1 stop bit
Protocol Output Format
The protocol format is equal to the format used by the TouchLine Exchange, each data message consists of a variable number of data records consisting of 4 hexadecimal digits (ASCII) each. In addition there are control characters in between:
<NUL> <head> <SP> <SP> ( <SP> .....) <CR LF> <NUL> ASCII NUL character <head> number of records - head inclusive (2 hex digits), message code (2 hex digits) <SP> ASCII space Four hexadecimal digits <CR LF> ASCII Carriage Return, Line Feed.
Message filtering
There is a data filtering system in AlphaCom to prevent that all reportable events in a high traffic situation are reported when it is not necessary. As default all stations in the system belongs to the report group called "MONITOR_ST_GROUP".
Not all the supported events are among the subset of events comprising the "MONITOR_ST_GROUP". Through special programming of the AlphaCom, events may be added or taken out of the reporting group (not supported by AlphaPro, use TST).