Specifications

1070 072 131-102 (96.08) GB
BUEP64 Protocol 9-1
9 BUEP64 Protocol
9.1 Introduction
A frequent application occurring in automated systems is the data ex-
change between complex or spatially distributed control systems.
This section discusses the BÜP64 protocol (Siemens 3964 / 3964R pro-
tocol) which can be loaded into the R500 and R500P computer modules.
The BÜP64 protocol transfers data across a point-to-point-connection, as
a result of which data can be exchanged between two modules with im-
plemented "3964" or "3964R" protocol; the principal difference between
the two protocols is that "3964R" for data security transmits a block
checksum according to the control sequence DLE ETX or DLE ETB and
uses an acknowledgement delay time of 2 s, whereas "3964" dispenses
with a block checksum and uses an acknowledgement delay time of 550
ms.
The user selects the communication protocol, "3964" or "3964R", by set-
ting the S2 DIP switch.
The user controls the "3964R / 3964" protocols by means of the standard
function modules R5INIT, R5REQ and R5CON:
R5INIT: initialises the computer modules concerned with data traffic;
R5REQ: starts a protocol job;
R5CON: acknowledges started protocol jobs;
The abbreviations RST and PST occur frequently throughout this docu-
mentation and are defined as follows:
RST: Requesting station
specifies the communications partner which starts the protocol job;
PST: Peripheral station
specifies the communications partner which responds to a received protocol job;