![TREBING + HIMSTEDT SPI 3 Скачать руководство пользователя страница 12](http://html1.mh-extra.com/html/trebing-himstedt/spi-3/spi-3_manual_1154873012.webp)
Installing the SPI 3
12
Trebing & Himstedt | SPI 3 | MODBUS RTU
Example:
In order to set the PROFIBUS address 68, turn the rotary switch for the 10’s
to 6, and the rotary switch for the units to 8.
Bus terminating resistor
Terminations of a PROFIBUS network must each be terminated with a bus
terminating resistor. Use standardized plugs with integrated terminating resistors.
Figure: Bus termination configuration for PROFIBUS (see PROFIBUS Norm)
Note!
Please observe the following when using the depicted passive terminating
resistor: Is the feeding voltage (+5 V) supplied by the device (SPI 3), the
PROFIBUS is shorted via the resistors when the device is disconnected
from voltage. PROFIBUS communication can be interrupted or completely
break down until the device is re-energized.
Use active resistors to avoid this problem, as in this case the terminating
resistors are fed with +5 V and GND independently from the device.
1 390
Ω
Pull-up resistance from Pin 3 to positive supply voltage at Pin 6
2 220
Ω
Cable terminating resistor between Pin 3 and Pin 8
3 390
Ω
Pull-Down resistor from Pin 8 to data reception potential at Pin 5
RUN
PB
TX
RX
X
10
X
1
Station
+5 V DC/DC
(Pin 6)
Data+
(Pin 3)
Data–
(Pin 8)
GND DC/DC
(Pin 5)
[1]
[2]
[3]