Technical data

Glossary

Software

456 System Manual, 07/2009, C79000-G8976-C222-07

Remote buffer

The remote buffer is set up only for redundant ST7cc. The ST7cc server recognizes whether

or not the redundant mode is required based on the existence of the redundancy license.

The remote buffer is organized as a ring buffer and records all incoming messages so that it

can be used as a data source for the redundant partner during a restart. If the partner of a

redundant ST7cc system starts up again, it can recognize the time for which messages are

missing and can request these from the redundancy partner. The remote buffer is necessary

to ensure data consistency when using a redundant ST7cc system.

Requested message

Polled messages are data messages of a station or node TIM with a special identifier

indicating that they were sent in response to a general request from the master station.

RJ-12

This describes a 6-pin connecting cable with a standardized modular (Western) connector.

RJ-45

This describes a 8-pin connecting cable with a standardized modular (Western) connector.

RS-232

RS-232 is a standard for serial (i.e. bit-by bit) data transmission with +12 V and -12 V

signals. RS-232 is a Recommended Standard of the Electronic Industries Association. For

the RS-232 interface, 9-pin and 25-pin connections with D-sub connectors are normal.

These are sub-miniature connectors with a D-shaped face.

RS-485

RS-485 is a standard for data transmission with 5 V differential signals. The RS-485

interface uses only one pair of wires and is operated in half duplex. The connection is

multipoint-compliant; in other words, up to 32 subscribers can be connected.

Send buffer

→

Image memory / send buffer

Send buffer principle

If a send message is transmitted using the send buffer principle, each time the message is

transferred to the TIM, it is entered completely in the send buffer. If such a message cannot

(or should not) be transmitted immediately, it may exist more than once in the send buffer.

When it is sent, the message is taken completely from the send buffer and transmitted.