VEGA VEGASON 54P…56P Profibus PA - Manual (Page 29)

VEGASON 54P … 56P 29
Electrical connection
3.3 Sensor address
In a Profibus system composed of Profibus
DP and Profibus PA subsystem, each partici-
pant must have a unique address. Each
participant, whether master or slave, is
accessed by means of its own address in
the bus system. The address of a partici-
pant, whether on DP or PA level, should be
assigned before connecting to the bus, be-
cause an address can be used only once. If
an address is used twice, interference in the
bus will be caused.
The address of an ultrasonic sensor can be
set in two ways:
- with the adjustment software VVO (soft-
ware addressing) or
- with the DIP switch block in the sensor
(hardware addressing).
VEGA Profibus sensors are delivered with
the address set at 126 (all DIP switches to
"ON").
Remember, in a Profibus system there are
max. 126 participants possible. When the
DIP switch is set to address 126 (or higher),
the address can be adjusted with the adjust-
ment software VVO, the adjustment module
MINICOM or another configuration tool (e.g.
PDM). However, there can be only one sen-
sor on the bus with address 126 (delivery
status) during address assignment via soft-
ware. For that reason, hardware addressing
(DIP switch) before connection to the bus is
recommended.
Hardware addressing
The DIP switches generate an address
number in the binary system. This means
that, from right to left (ascending), any switch
represents a number twice as high as the
previous switch on the right. The corre-
sponding number in the decimal system
results from the sum of all switches set to
"ON". In the illustration, you see the decimal
number that corresponds to each individual
DIP switch.
DIP switch 8 corresponds to the number 128,
switch 1 corresponds to the number 1 and
switch 3 corresponds to the decimal number
4.
4
16
64
64 + 16 + 4 = 84
8 7 6 5 4 3 2 1
ON
1
2
4
8 16
32
64
128
8 7 6 5 4 3 2 1
Example 1
The switches 3, 5 and 7 are set to "ON". The
address is then:
DIP switch 3 to "ON" means 4
DIP switch 5 to "ON" means 16
DIP switch 7 to "ON" means 64
The sum is:
4 + 16 + 64 = Address 84