Serial Interfaces With Peer-To-Peer Protocol - Siemens 6RA7086-6KS22 Operating Instructions Manual

05.05
Connection example for a USS bus
Master
(Bus terminating
resistors activated)
SIMATIC S5
CP524 with RS485
-module ...0AA43
(Jumper X3: 20-18 -->
2-wire cable)
12 10
14
X3
4
SUB-D connector
15-pin
1) The interface cable shields must be connected directly on the converter with the lowest possible
impedance to converter or cubicle earth (e.g. via clamp).
2) Twisted cable, e.g. LIYCY 2x0.5 sqmm; with longer cables, an equipotential bonding conductor
must be used to ensure that the difference in frame potentials between nodes stays below 7 V.

9.13.2 Serial interfaces with peer-to-peer protocol

The term "Peer-to-peer link" refers to a "Link between partners of equal status". In contrast to the
classic master/slave bus system (e.g. USS and PROFIBUS), the same converter can function as both
the master (setpoint source) and the slave (setpoint receiver) in a peer-to-peer link.
Signals can be transferred in fully digital form from one converter to another via the peer-to-peer link,
for example:
− Velocity setpoints for producing a setpoint cascade, e.g. on paper, foil and wire-drawing
machines and on fiber-drawing machinery.
− Torque setpoints for closed-loop load distribution controls on drives that are coupled
mechanically or via the material, e.g. longitudinal-shaft drives on printing presses or S-roll drives
− Acceleration setpoints (dv/dt) for acceleration precontrol on multi-motor drives.
− Control commands
Useful data which can be transferred via the peer-to-peer link
Sheets G173 and G174 in Section 8 show how useful data can be interconnected and list the
parameters relevant for configuring peer-to-peer links. Any connectors can be parameterized as
transmit data (numeric representation: 100% equals 4000h = 16384d).
Parameters cannot be transferred via the peer-to-peer link.
Transfer of double-word connectors:
In the receive direction, the values of any two adjacent connectors (K) are combined to form a double-
word connector (KK) (e.g. K6001 and K6002 to KK6081). These double-word connectors can be
connected in the usual way to other function blocks. For details of how to connect with double-word
connectors, see Section 9.1, subsection "The following rules apply to the selection of double-word
connectors".
In the transmission direction, a double-word connector is applied by entering the same double-word
SIEMENS AG 6RX1700-0AD76
SIMOREG DC Master Operating Instructions
Slave 1
(Bus terminating
resistors deactivated)
Rx Tx
8 6 4
X3
-
-
+
59
11
150 Ω
2)
1)
(Bus terminating
resistors deactivated)
6RA70
Rx
Tx
+
+ -
58 59
Function descriptions
Slave 2
6RA70
Rx
Tx
+
+
58
Slave n (n<=31))
(Bus terminating
resistors activated)
6RA70
Rx
Tx
+
-
+
59 58
9-27