Siemens simatic c7-621 Hardware Installation Manual page 50

Configuring an MPI Network
Terminating Figure 3-2 shows the switches on the RS 485 repeater for activating the
Resistor on the RS
terminating resistor.
485 Repeater
Figure 3-2
Example of
Figure 3-3 shows a possible MPI configuration in which the terminating
Termination in an
resistor must be activated.
MPI Network
C7
À
S7-300
OP 25
À
* Only connected during installation/maintenance via a tap line
À Terminating resistor activated
Figure 3-3 Activating Terminating Resistors in an MPI Network
3-6
DC
L+ M PE M 5.2
24 V
ON
ON
SIEMENS
Terminating Resistor on the RS 485 Repeater
PG
S7-300
RS 485
repeater
Connecting
cable
PG*
Terminating resistor
bus segment 1
Terminating resistor
bus segment 2
S7-300
OP 25
À
C7-621 / C7-621 AS-i Control Systems
C79000-G7076-C621-01