NORD Drivesystems BU0020 - Manual (Page 52)

PROFIBUS DP – Supplementary manual options for NORD - Frequency Inverters
52 BU 0020 GB-2612
SDN Send data with no acknowledge, allows the transmission of broadcast telegrams
(unacknowledged telegrams).
The PROFIBUS DP master cyclically reads the input information from the connected DP slaves and
cyclically writes the output information to the DP slaves.
PROFIBUS DP masters exist as
- modules within a PLC
- CPU modules with integrated PLC
- standard PC modules
- Stand-alone-boards
Pos: 65 /Anleitungen/Bussysteme/4. Protokoll/Profibus [BU0020]PROFIBUS Slave @ 1\mod_1335529366075_388.docx @ 24649 @ 2 @ 1
5.6 PROFIBUS slave
PROFIBUS DP slaves are peripheral devices such as I/Os, drive units, HMIs, valves, measurement
transponders, frequency inverters. The DP slaves do not receive any access rights, i.e. they can only
confirm messages from the master or send messages to the master when requested. DP slaves are
designated as passive participants. A slave reads in input information and sends out output
information to the peripherals. Because a slave only requires a small portion of the protocol, they are
simple to implement in the PROFIBUS system configuration. The amount of input and output
information depends on the device and can be up to a maximum of 246 input and 246 output bytes.
All data which a PROFIBUS master requires for the exchange of data (e.g. I/O area) with the slave
and its implementation is provided by means of a DeviceMasterFile (GSD file) which is specific to
the particular manufacturer.
The slaves are decentrally coupled to the PLC control unit or the automation device via the transfer
medium (PROFIBUS cable and RS485) and complete the configuration of the system.
Pos: 66 /Anleitungen/Bussysteme/5. Parametrierung/!Kapitel Parametrierung [Profibus BU0020] @ 1\mod_1335529698501_388.docx @ 24674 @ 1 @ 1
Di
re
c
t
re
s
po
ns
Confirmation with
data
Command, data (if necessary)
D
P ma
s
te
r
D
P s
lav
e
Command, data (if necessary)
DP maste
r
DP sla
ve