The IEC 60870-5-101, Dialup Master protocol stack implements the IEC 60870-5-101 protocol in combination with integrated automatic calling (ACU Automatic Calling Unit) specifically for operation based on a variety of dialup connections, such as PSTN (Public Switched Telephone Network), GSM, ISDN and others.
IEC 60870-5-101, Dialup Master supports virtually all types of Hayes compatible modems. It features automatic recognition of the connected modem type. Configuration of additional initial modem strings is possible. The system performs cyclic operation checks on all modems during runtime, any modem failure is signalled to the super ordinate system.
IEC 60870-5-101, Dialup Master is
capable of managing any number of
stations and modems. There is rule-based connection setup to a specified
station:
- cyclically, at a predefined interval
- spontaneously following a switching command transmitted to a station
- spontaneously with the connection setup initiated by the slave station
- manually through the explicit command to dial up
- manually through a general poll
The rules for connection teardown:
- the configured timeout for the maximum connect time was exceeded
- no ASDUs (Application Service Data Unit) were transmitted within a defined time interval
The associations between modems
and the stations to be dialled up can be freely configured. In a typical
configuration, several modems can be used at the same time to dial to several
stations. The assignment between modems and stations can be made as required
during operation rather than using a fixed definition. However, such a fixed
assignment (one modem, one substation) can be easily configured.
The stati of modems,
connections and substations can be monitored through internal indications and
reported to the super ordinate system. If a station does not respond within a
predefined timeout or connection setup fails, all associated data points are
dispatched to the super ordinate system with the quality identifier
"invalid"/"not topical".
The communication accepts
both "balanced" and "unbalanced" transmission modes.
