Спецификация протокола Profibus
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PROFIBUS-Specification-Normative-Parts-2:1997
Copyright by PNO 1997 - all rights reserved
PROFIBUS User:
Control Station
(Central Processing)
or Field Device
^
!
!
+--------!--------+
!+-------+-------+!
!! User !!
!! Interface !!
!! FDL/APP !!
!! Processor !!
!+-------+-------+!
!+-------+-------+!
PBC !! UART !!
!+-------+-------+!
!+-------+-------+!
!! Transceiver !!
!! (electrical !!
!! isolation) !!
!+-------+-------+!
+--------!--------+
!
!
Medium -------------------+-----------------
Figure 2-A.3 PROFIBUS Controller (PBC)
For the adaption to the different field automation units and devices mostly
three variants of the PROFIBUS Controller (Controller_type) are used that differ
distinctly in expense (see Fig. below):
Field Device or Field Device or Field Device, if
Control Station Control Station free Capacity of
with
≥
500 kbit/s with
≤
500 kbit/s UART and Processor
with
≤
200 kbit/s
! ! !
! ! !
!PI !PI !SI
+-----+-----+ ! !
!DP-RAM/DMA ! ! !
+-----+-----+ ! !
+-----+-----+ ! !
! µP with ! +-----+-----+ !
! ROM/RAM !
A
!DP-RAM/DMA !
B
!
C
! INT/TIMER ! +-----+-----+ !
+-----+-----+ +-----+-----+ !
+-----+-----+ ! 1 Chip MC ! !
! UART ! ! with UART ! !
+-----+-----+ +-----+-----+ !
! ! !
+--------------------- --------------------+
!
+--------+--------+
! Transceiver !
!(elec. isolation)!
+--------+--------+
!
!
Medium ------------------+-------------------
Where: PI Parallel Interface
SI Serial Interface
DP-RAMDual Port RAM
DMA Direct Memory Access
Figure 2-A.4 Variants of PBC (Controller_type)
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PROFIBUS-Specification-Normative-Parts-2:1997
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A:For data signalling rates at, or in future also above, 500 kbit/s a suitable
microprocessor (e.g. 80186) with adequate memory and peripheral devices
becomes necessary for the FDL/APP processor. The interface to the user is
realized preferably by a Dual Port RAM or a DMA.
B:For data signalling rates ≤ 500 kbit/s single chip microprocessors with UART
device (e.g. 80C51FA, V25 [µPD 70322]) are now suitable. As above a Dual
Port RAM or DMA is preferred for the user interface.
C The minimum expense results from shifting the FDL/APP protocol into the
device CPU. For this a UART interface shall be free and free capacity in the
device processor shall be available for the FDL/APP protocol. Often the
obtainable data signalling rate is not above 200 kbit/s.
2-A.3System with several Bus Lines to one Control Station
The division in several self-sufficient bus lines offers an alternative for pure
master - slave systems, which need more than 32 stations in each system, and
which cannot employ repeaters. These lines are operated in time multiplexing by
one master station or in parallel with one master station each. For a layout of
e.g. four lines according to version 1, 125 stations are permissible altogether.
With regard to simplicity, availability and reaction time such a layout is espe-
cially favourable. In case of breakdown of one line the remaining stations are
able to communicate with the control station, whereas for a single line all
stations would be inaccessible.
Depending on the data signalling rate of the individual lines two structures
exist that differ in expense. For up to about 200 kbit/s, a bus controller of
PBC Type A as master station is able today to support 4 UART devices and there-
fore manage four bus lines, see following Figure:
+-----------------------+
! Control Station !
! (Central Processing) !
! !
+-----------------------+
! Master Station !
+-----+-----+-----+-----+
!UART1!UART2!UART3!UART4!
+--+--+--+--+--+--+--+--+
! ! ! !
! ! ! !
! ! ! !
! ! ! !
Bus1! Bus2! Bus3! Bus4!
Figure 2-A.5 Several Buses controlled by one Master (PBC)
For data signalling rates above 200 kbit/s a separate bus controller as master
station for each line becomes necessary. The number of buses possible depends on
the capability of the control station, because it shall coordinate the masters
(see Fig. below).
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PROFIBUS-Specification-Normative-Parts-2:1997
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+--------------------------------+
! Control Station !
! (Central Processing) !
! !
+----------+----------+----------+
! Master ! ! Master !
! Station ! . . . ! Station !
! 1 ! ! n !
+----+-----+----------+----+-----+
! !
! !
! : : : !
! !
Bus 1 ! Bus n !
Figure 2-A.6 Several PBCs in one Control Station
2-A.4Redundant Control Station
Redundancy of the complete control station is required to increase the avail-
ability of systems with only one master station (master - slave system). Merely
a doubled bus controller would not provide the necessary availability to the
control station in case of power failure. The basic layout may be with or with-
out redundant transmission techniques (see Fig. below):
+---------------------+ +---------------------+
! Control Station 1 ! ! Control Station 2 !
! (Central ! Direct ! (Central !
! Processing) !<-------->! Processing) !
! ! Coupling ! !
+---------------------+ +---------------------+
! Master Station 1 ! ! Master Station 2 !
+-------+-----+-------+ +-------+-----+-------+
! : ! :
! : ! :
! : ! :
Bus a -------+-----:--------------------------+-----:--------
: :
(Bus b) .............!................................!........
Figure 2-A.7 Redundant Control Station
In the above concept always only one control station is active, while the other
is waiting in updated condition (hot standby). By means of activity control
(time-out) of the bus lines the standby station is able to independently take
over the control function upon failure of the control station. For this purpose
it shall hold a current data record, which is exchanged between the units pref-
erably by direct coupling. At system start-up the active control station is
determined by prioritization.
2-A.5Bus Analysis/Diagnostic Unit (Bus Monitor)
During start-up, maintenance and in case of failure a control station is able to
perform operational tests only to a limited extent. Extensive statements about
the state of the PROFIBUS System are possible only with an additional ana-
lyse/diagnostic device (bus monitor) which may be connected to the bus at any
place in the field. This unit has three operating modes:
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- analysis mode
- diagnostic mode
- control station mode (standard mode PHY/FDL/APP)
In analysis mode events are acquired and analyzed on the PROFIBUS in certain
time intervals and according to different criteria. The device operates purely
passively as a monitor of all messages and does not influence the bus operation.
The diagnostic mode serves to detect and localize errors, to determine the
system configuration and system state and to provide a lucid display of the
acquired and analyzed station and error conditions. The diagnostic mode requires
the transmission of dedicated messages and the triggering of certain actions
such as special error states, bus load or the self test in the other stations.
This mode is only permissible for the master station.
In control station mode the central processing function is performed. It is
essential for the retention of bus operation after shut-down or failure of the
active control station. The central control function may be taken over thereby
to a limited extent only (see conditions for redundant control stations). The
control station mode may also be used for the stepwise start-up of new stations
in the PROFIBUS System.
The Figure below shows roughly the layout of such an analysis/diagnostic device.
A standard PROFIBUS coupling for master stations is used (Type A), with an
analysis/diagnostic computer (e.g. PC) coupled to the user interface. A standard
keyboard with screen serves to operate and display PROFIBUS functions and
states. This computer has a standard serial interface (CCITT V.24, TTY) for
logging system conditions.
+----------+
! -------- !
! !Screen! !
+-------------+ ! -------- !
SI ! Analysis / <----->----------+
V.24/TTY <----> Diagnostic !
(Printer) ! Computer ! +----------+
! (PC) <-----> Keyboard !
+-----^^^-----+ +----------+
PI !!!
+-----vvv-----+
! PROFIBUS !
! Controller !
! Master !
! Station !
!
≤
1,5 Mbit/s!
+---+-----+---+
! :
! :
Bus a ---------------------+-----:---------------------------
:
(Bus b) .........................!...........................
Where:
SI Serial Interface
PI Parallel Interface
Figure 2-A.8 Bus Analysis/Diagnostic Unit
Page 45
PROFIBUS-Specification-Normative-Parts-2:1997
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2-A.6Performance of Message Rate, System Reaction Time and Token Rotation Time
The message rate R
SYS
in the system corresponds to the possible number of mes-
sage cycles per second (see Part 4, clause 4.2, formula (23)). The maximum
system reaction time (also called station or bus request time) for cyclic
send/request (polling) from one master station to n slave stations is computed
from the message cycle time and the number of slave stations (see Part 4, clause
4.2, formula (24)).
For the following example calculation the times T are converted into t (seconds)
and set as follows:
t
SDR
= 0,5 ms, t
ID
= 1 ms (or t
SYN
+ t
SM
, if > 1 ms) and DATA_UNIT = 2, 10, 50
octet, assuming np = 30 slave stations. The request frame is in each case with-
out DATA_UNIT (see Part 4, subclause 4.6.1A), while the response frame has a
variable DATA_UNIT (see Part 4, subclause 4.6.3B).
The formulas (22), (23) and (24) described in Part 4, clause 4.2 yield the
values listed in the table below for message cycle time, message rate and system
reaction time versus data signalling rate, DATA_UNIT and number of slave
stations. Message repetition and the time T
TD
are not considered. Token transfer
times are irrelevant, because there is only one master station in the system.
The values are rounded. See also Fig. 2-A.11 and Fig. 2-A.12.
Table 2-A.1
+-----------+-----------------------------------------------+
! ! Data Signalling Rate [kbit/s] !
! DATA_UNIT ! !
! ! 9,6 ! 19,2 ! 93,75 ! 187,5 ! 500 ! 1500 !
+===========+=======+=======+=======+=======+=======+=======+
! ! t
MC
[ms] Time for One Message Cycle !
! ! !
! 2 octets ! 24 ! 12 ! 3,5 ! 2,5 ! 1,9 ! 1,6 !
! ! ! ! ! ! ! !
! 10 octets ! 33 ! 17 ! 4,4 ! 3 ! 2,1 ! 1,7 !
! ! ! ! ! ! ! !
! 50 octets ! 79 ! 40 ! 9,2 ! 5,3 ! 2,93 ! 2 !
+
-----------+-------+-------+-------+-------+-------
+-------+
! ! R
SYS
[N/s] System Total Message Cycles/second!
! ! !
! 2 octets ! 42 ! 82 ! 287 ! 400 ! 535 ! 615 !
! ! ! ! ! ! ! !
! 10 octets ! 30 ! 60 ! 226 ! 337 ! 488 ! 594 !
! ! ! ! ! ! ! !
! 50 octets ! 12 ! 25 ! 108 ! 188 ! 341 ! 506 !
+
-----------+-------+-------+-------+-------+-------
+-------+
! ! t
SR
[ms] System Reaction (Latency) Time !
! ! with 30 Slave Stations !
! ! ! ! ! ! ! !
! 2 octets ! 711 ! 364 ! 105 ! 75 ! 56 ! 49 !
! ! ! ! ! ! ! !
! 10 octets ! 986 ! 502 ! 133 ! 89 ! 62 ! 51 !
! ! ! ! ! ! ! !
! 50 octets ! 2,4s ! 1,2s ! 276 ! 159 ! 88 ! 60 !
+-----------+-------+-------+-------+-------+-------+-------+
In a system with several master stations the system reaction time t
SR
depends
additionally on the real token rotation time t
RR
. Fig. 2-A.13 shows the bounds
of t
RR
versus the number of master stations and high priority messages for
93,75, 500 and 1500 kbit/s. Message repetition and the time T
TD
are not
considered. The computation is based upon the token cycle time T
TC
according to
Fig. 2-A.9 and the combined token and message cycle time T
TC/MC
according to
Fig. 2-A.10.
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Copyright by PNO 1997 - all rights reserved
+----------+
na !Token na !------+
+----------+ !
T
TF
T
ID
!
! +----------+
na+1 +---->!Token na+1!---+
+----------+ !
!
Token Cycle Time T
TC
V
+<--------------------->+
T
TC
= T
TF
+ T
ID
; T
TF
= 33 bit (2-A.1)
Figure 2-A.9 Cycle Time T
TC
+-----+
na !Token!---+
+-----+ !
T
TF
T
ID'
!
! +---------+ +-----+
na+1 +--->!Send/Req.!---+ +--->!Token!
+---------+ ! ! +-----+
T
S/R
T
SDR
T
ID
! !
! +----------+ !
np +--->!Ack./Resp.!---+
+----------+
T
A/R
Token + Message Cycle Time T
TC/MC
+<--------------------------------------------------->+
T
TC/MC
= T
TF
+ T
ID'
+ T
S/R
+ T
SDR
+ T
A/R
+ T
ID
(2-A.2)
Figure 2-A.10 Cycle Time T
TC/MC
Message Cycle:
Send/Request Data with Reply: T
S/R
= 66 bit
Response with 10 octet DATA_UNIT: T
A/R
= 209 bit
The following implementation dependent times were chosen:
Token Cycle: t
ID
= 0,5 ms
Token + Message Cycle: t
ID
= 0,5 ms ; t
ID'
= 1 ms ;
t
SDR
= 0,5 ms
Page 47
PROFIBUS-Specification-Normative-Parts-2:1997
Copyright by PNO 1997 - all rights reserved
0
100
200
300
400
500
600
10 20 100 200 500 1500
N/s
kbit/s
1)
2)
3)
2 octet DATA_UNIT: 1)
10 octet DATA_UNIT: 2)
50 octet DATA_UNIT: 3)
Figure 2-A.
11
System Total Message Cycles R
SYS
0
100
500
1000
10 20 100 200 500 1500
ms
kbit/s
1500
30 passive Stations:
1) to 3) as in Figure 2-A.11
1) 2) 3)
Figure 2-A.
12
System Reaction Time t
SR
Page 48
PROFIBUS-Specification-Normative-Parts-2:1997
Copyright by PNO 1997 - all rights reserved
1
2
5
10
10 2015 25 305
ms
na
20
2 32
50
100
200
93,75 kbit/s: 1)
500 kbit/s: 2)
1500 kbit/s: 3)
10 octet DATA_UNIT
na Message
Cycles per
Token Rota-
tion
1 Message
Cycle per
Token Rota-
tion
Number of
Master
Stations
1)
2)
3)
3)
2)
1)
Figure 2-A.
13
Real Token Rotation Time t
RR
Page 49
PROFIBUS-Specification-Normative-Parts-3:1997
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PROFIBUS Specification - Normative Parts
Part 3
Data Link Layer Service Definition
Page 50
PROFIBUS-Specification-Normative-Parts-3:1997
Copyright by PNO 1997 - all rights reserved
Contents
Page
1 Scope ...............................................................51
2 Normative References ................................................51
3 General .............................................................51
4 PROFIBUS Layer 2 Interface ..........................................51
4.1 FDL User - FDL Interface ............................................51
4.1.1 Overview of Services ................................................52
4.1.2 Overview of Interactions ............................................53
4.1.3 Detailed Specification of Services and Interactions .................56
4.1.3.1 Send Data with Acknowledge (SDA) ....................................56
4.1.3.2 Send Data with No Acknowledge (SDN) .................................59
4.1.3.3 Send and Request Data with Reply (SRD) ..............................60
4.1.3.4 Cyclic Send and Request Data with Reply (CSRD) ......................64
4.2 FMA1/2 User - FMA1/2 Interface ......................................69
4.2.1 Overview of Services ................................................69
4.2.2 Overview of Interactions ............................................71
4.2.3 Detailed Specification of Services and Interactions .................72
4.2.3.1 Reset FMA1/2 ........................................................72
4.2.3.2 Set Value FMA1/2, Read Value FMA1/2 .................................73
4.2.3.3 Event FMA1/2 ........................................................75
4.2.3.4 Ident FMA1/2 ........................................................75
4.2.3.5 LSAP Status FMA1/2 ..................................................76
4.2.3.6 Live List FMA1/2 ....................................................78
4.2.3.7 (R)SAP Activate FMA1/2, SAP Deactivate FMA1/2 .......................78
5 Management (FMA1/2) .................................................85
5.1 General Description of FMA1/2 Functions .............................85
5.2 FDL - FMA1/2 Interface ..............................................85
5.2.1 Overview of Services ................................................86
5.2.2 Overview of Interactions ............................................87
5.2.3 Detailed Specification of Services and Interactions .................88
5.2.3.1 Reset FDL ...........................................................88
5.2.3.2 Set Value FDL, Read Value FDL .......................................88
5.2.3.3 Fault FDL ...........................................................91
5.3 PHY - FMA1/2 Interface .............................................92
5.3.1 Overview of Services ................................................92
5.3.2 Overview of Interactions ............................................93
5.3.3 Detailed Specification of Services and Interactions .................94
5.3.3.1 Reset PHY ...........................................................94
5.3.3.2 Set Value PHY, Read Value PHY .......................................94
5.3.3.3 Event PHY ...........................................................96