Specifications

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General Information Section 5-1
5.1 General Information
Via the serial procedure 3964, the operating terminals can be connected to a pro-
grammable controller.
The logical part of the 3964 protocol, RK512, is adapted to the communication with
a Siemens PLC via a CP525, or compatible, communications processor.
The software components of the system are fully adapted to the parameters and
marginal conditions of the protocol 3964/ RK512.
This offers the user the following advantages:
- Random read and write access to any data within the PLC. Data of existing PLC
programs can be displayed and modified directly in the operating terminal. It is
not necessary to adapt the PLC program to the operating terminal in any respect
since it is not required that communications data be stored in a specified ad-
dress area or data type area.
- The operating terminal automatically polls the freely definable data areas for
cyclic data.
- Simultaneous connection of the operating terminal and the programming unit
(PU) is possible.
- Only a minimum of configuration is required for the installation of the data hand-
ling block required in the PLC in addition to the protocol function blocks.
- Minimal increase of the cycle time in the PLC.
- The protocol provides error control. Transmission errors are detected and, if
possible, eliminated by repeating the transmission. A noise-immune interface
hardware in accordance with the 20 mA current loop interface standard permits
the application even in a harsh industrial environment.
- The parameters of the interface SER1 are assigned in the programming soft-
ware in a protocol specific manner and are stored in the application description.
Modifying of the parameters is possible in the setup-mask or in each other I/O-
mask of the terminal at any time.
- The programming system provides a maximum of support to the operator in
programming the operating terminal. The definitions (abbreviations) used here
are identical with the definitions used within the PLC program.