Bosch Rexroth Tightening System 350 - Fundamentals of the 3964 R and RK512 Tightening Data Output

260/641 Bosch Rexroth AG | Tightening Technology 3 608 878 300
System 350 | 3 608 878 300/2019-03
6.3.1 Fundamentals of the 3964R and RK512 tightening data output
6.3.1.1 Protocol description
Data exchange between the tightening system and the partner controllers is implemented physically via
a serial interface. In this case, the serial interface (X3C1, RS232) can be used. 3964R or RK512
(Siemens) is used as the protocol for data transfer between the units.
In the OSI layer model, the 3964R protocol describes transfer layers 1 (bit transfer layer) and 2 (backup
layer). Additionally, layer 4 (transport layer) is defined in the RK512 protocol. Thus, the 3964R protocol
is a subset of the RK512 (Siemens) protocol. Both protocols will be described in more detail below. The
parts that are not included in the 3964R protocol are highlighted.
Write-only access is implemented in the Tightening System 350 when transferring data with 3964R/
RK512, i.e. the partner controller sends data (see page 262) to the tightening system which in turn sends
data (see page 262) to the partner controller. These are point-to-point connections via the serial
interface.
Fig. 6–36: OSI layer model for 3964R and RK512 protocols
Due to the conduction physics, cross-talk between transmission path (TX) and receipt path (RX) may
result with open, shielded lines (e. g. RS232). As a consequence of this effect, the relevant signals and
signal levels can no longer be correctly presented and interpreted. This results in loops in the transmission
and/or receipt routine of the operating system.
 Always connect lines with the characteristics specified above with a corresponding communication
partner in order to avoid the undesired cross-talk effect.
Bit transfer layer
Determination of the physical transfer of data bytes
Backup layer
Transfer of the data bytes with 3964R. Start and end characters
are added, the transfer could possibly be repeated if there is a
failure.
Not available, since it is just a point-to-point connection.
Transport layer
Every command telegram that has been correctly received is
answered with a reaction telegram.
Layer 4
Layer 3
Layer 2
Layer 1
RK512
3964R
ASCII driver Printer driver