Allen-Bradley 857-VPA3CG User manual

User Manual
Original Instructions
857-VPA3CG Profibus DP Option Module
Catalog Number 857-VPA3CG
Summary of Changes This publication contains new and updated information as indicated in the
following table.
The Allen-Bradley® 857 protection relays can be connected to the PROFIBUS
DP by using an external communications device 857-VPA3CG. The relay can
then be monitored from the host system.
PROFIBUS is a vendor-independent, open fieldbus standard for a wide range of
applications in manufacturing, process, and building automation. Vendor
independence and openness are guaranteed by the PROFIBUS standard EN
50170. With PROFIBUS, devices of different manufactures can communicate
without special interface adjustments. PROFIBUS can be used for both high-
speed time critical data transmission and extensive complex communication
tasks. The PROFIBUS family consists of three compatible versions that are
defined later in this manual.
Topic Page
Summary of Changes 1
PROFIBUS-DP 2
PROFIBUS-PA 2
PROFIBUS-FMS 2
PROFIBUS-DP Device Profiles 2
Installation and Commissioning 6
Type Files 7
Dimensions 9
Specifications 10
Topic Page
Added dimension graphic 9

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857-VPA3CG Profibus DP Option Module
PROFIBUS-DP Optimized for high speed and inexpensive hook-up, this PROFIBUS version is
designed especially for communication between automation control systems and
distributed I/O at the device level.
PROFIBUS-DP can be used to replace parallel signal transmission with 24V or
0...20 mA.
PROFIBUS-PA PROFIBUS-PA is designed especially for process automation. It permits sensors
and actuators to be connected to one common bus line even in intrinsically safe
areas. PROFIBUS-PA permits data communication and power over the bus using
2-wire technology according to the international standard IEC 1158-2.
PROFIBUS-FMS PROFIBUS-FMS is the general-purpose solution for communication tasks at the
cell level. Powerful FMS services open up a wide range of applications and
provide great flexibility. PROFIBUS-FMS can also be used for extensive and
complex communication tasks.
PROFIBUS specifies the technical and functional characteristics of a serial
fieldbus system with which decentralized digital controllers can be networked
together from the field level to the cell level. PROFIBUS distinguishes between
master devices and slave devices.
Master devices determine the data communication on the bus. A master can send
messages without an external request when it holds the bus access rights (the
token). Masters are also called active stations in the PROFIBUS protocol.
Slave devices are peripheral devices. Typical slave devices include input/output
devices, valves, drives, and measuring transmitters. They do not have bus access
rights and they can only acknowledge received messages or send messages to the
master when requested to do so. Slaves are also called passive stations.
PROFIBUS-DP Device Profiles This section outlines the different PROFIBUS-DP device profiles.
Continuous Mode with Fixed Data Set
In this mode, the 857 protection relay is sending a configured set of parameters
continuously to the PROFIBUS-DP master.
Calculation of the PROFIBUS-DP Buffer Length
The needed buffer length for PROFIBUS-DP data transfer depends on the
biggest offset of any activated parameter and the size of this parameter. The offset
and the activation for each available parameter are configurable.

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857-VPA3CG Profibus DP Option Module
The device calculates the needed buffer length. For example, if the device's
display shows:
InBuf 32 byte
OutBuf 0 byte,
select the corresponding module "INPUT: 32 Byte" from the .gsd file (for
example, VPA_00F7.gsd) when configuring the PROFIBUS-DP master for this
device.
The following example reveals the algorithm that is used by the supplier of this
device to calculate the needed PROFIBUS-DP buffer length:
Example:
•The parameter Eimp (imported active energy) has the biggest offset, 30, of
all activated PROFIBUS-DP data items in InBuf.
•The size of Eimp item is 4 bytes.
•The parameter Direct05C (Direct Operate Object 5 Close) has the
biggest offset, 13, of all activated PROFIBUS data items in OutBuf.
•The size of Direct05C is 1 byte.
•Both buffers are forced to the same length.
Input:
Offset of the last occupied byte:
Round up to next 2n(n is an integer):
Round up to next integer ----* 6:
Output:
Offset of the last occupied byte:
Round up to next 2n (n is an integer):
Round up to next integer ~ 4:
After restarting, the device displays these buffer sizes:
InBuf 32 byte
OutBuf 0 byte,
If both buffers are in use in the continuous mode, the length of the smaller buffer
is forced to match the longer buffer. In the example: 24= 16 is forced to 26= 64.
30 4 1–+33=
33log log25.044=
2664=
13 1 1–+13=
13log log23.700=
2416=

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Select the corresponding module "INPUT/OUTPUT: 64 Byte" from the .gsd
file (for example, VPA_00F7.gsd) when configuring the PROFIBUS DP master
for this device.
Request Mode
Using the request mode, it is possible to read all available data from the 857
protection relay and still use only a short buffer for PROFIBUS data transfer.
The drawback is the slower overall speed of the data transfer and the need of
increased data processing at the PROFIBUS master as every data item must be
separately requested by the master from the slave.
After setting the PROFIBUS driver of the device into request mode, the device
will restart (wait approximately 30 seconds). After restarting the device will
ignore parameter offsets and will display the following fixed buffer sizes:
InBuf 8byte
OutBuf 8byte,
Select the corresponding module "INPUT/OUTPUT:8 Byte" from the .gsd file
(for example, VPA_00F7.gsd) when configuring the PROFIBUS-DP master for
this device.
Data Request Message from the PROFIBUS Master
The request is 8 bytes long consisting of three fields.
The Identifier word, ID, contained in the Data Request Message, consists of 3
fields with a bit configuration is shown below.
IMPORTANT
The recommended maximum size for output buffer in continuous mode is
64 bytes.
IMPORTANT
It is not possible to read continuously only one single data item. In request
mode, request at least two items in turn to get updated data from the device.
ID(1)
(1) Type and number of the requested data.
IND(2)
(2) Index 0…65,535 of the parameter member to be requested or 0 if the parameter is scalar.
VALUE(3)
(3) Not used.
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7
Request Type(1)
(1) 0001 Read (0010 = Write).
SM(2)
(2) 0 Spontaneous bit (not used).
Parameter Number(3)
(3) 0... 2047 Each available data item in the device has a fixed parameter number.
b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0

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857-VPA3CG Profibus DP Option Module
Data Response Message from the 857 Relay
The response is eight bytes long consisting of three fields.
The Identifier word, ID, contained in the Data Request Message, consists of 3
fields with a bit configuration is shown below.
Error codes in value field in case of response type 0111.
Request and Response Messages Examples
The master requests the measured active power from the device. The hexadecimal
byte values are:
The slave responds with the active power value.
The hexadecimal byte values are:
ID(1)
(1) Type and number of the requested data.
IND(2)
(2) Requested index.
VALUE(3)
(3) Value of the requested data or error code.
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7
Response Type(1)
(1) 0001 Read (0010 = Write).
0111 Request Rejected.
SM(2)
(2) 0 Spontaneous bit (not used).
Parameter Number(3)
(3) 0…2047 The number of the requested parameter.
b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
0 Illegal parameter
18 Other fault
101 Unknown request type
ID(1)
(1) 1 Request type is read.
0 00 Parameter number of active power P is 0.
IND(2)
(2) 00 00 Index is 0.
VALUE(3)
(3) 00 00 00 00 Dummy value.
10 00 00 00 00 00 00 00
ID(1)
(1) 1 Response type is “Value is ready”.
000 Parameter number is 0. (Copy of request message parameter number).
IND(2)
(2) 00 00 Index is 0 (Copy of request message index).
VALUE(3)
(3) 00 00 OD 7A The active power is 3450 kW (ID7A16 = 345010).
10 00 00 00 00 00 0D 7A

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Installation and
Commissioning
External Adapter
The external adapter is connected to the 'REMOTE'-port (connector X5) on the
relay back panel with 857-VX007-F3 cable.
Figure 1 - Connecting External Adapter
Setting the PROFIBUS Address and Other Parameters
The PROFIBUS parameters can be changed from the relay front panel or by
SetPointPS program.
VX 007 Cable
X5
Relay back panel
“Remote” port
VPA 3 CG (Attached
to 35 mm DIN RAIL)
PROFIBUS
Table 1 - PROFIBUS Parameters
Mode PROFIBUS mode: Continuous / Request
bit/s Speed between the relay and adapter
InBul(1)
(1) Parameters are read only.
Input(2) buffer length
(2) Input: Relay -> PROFIBUS master.
Output: PROFIBUS master -> Relay.
OutBul(1) Output(2) buffer length
Addr PROFIBUS address (range 1...126)
Conv(1) Type of PROFIBUS adapter (VE, HMS, -)

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857-VPA3CG Profibus DP Option Module
Type Files GSD-file
;================================================
===================
;GSD file for VPA
;
;2002-07-22 JPH/Vaasa Electronics Ltd.
;
;File : VPA_00F7.GSD
;================================================
===================
#Profibus_DP
; Unit-Defination-List:
GSD_Revision = 2
Vendor_Name = "Vaasa Electronics Ltd."
Model_Name = "VPA"
Revision = "1.0"
Ident_Number = 0x00F7
Protocol_Ident = 0
Station_Type = 0 ; DP-Slave
FMS_supp = 0 ; no FMS/DP Mixed Device
Hardware_Release = "HW1.0"
Software_Release = "SW1.0"
;
9.6_supp = 1 ;baud rate supported
19.2_supp = 1 ;baud rate supported
93.75_supp = 1 ;baud rate supported
187.5_supp = 1 ;baud rate supported
500_supp = 1 ;baud rate supported
1.5M_supp = 1 ;baud rate supported
3M_supp = 1 ;baud rate supported
6M_supp = 1 ;baud rate supported
12M_supp = 1;baud rate supported
; Duration to answer a request by a responder
MaxTsdr_9.6 = 60
MaxTsdr_19.2 = 60
MaxTsdr_93.75 = 60
MaxTsdr_187.5 = 60
MaxTsdr_500 = 100
MaxTsdr_1.5M = 150
MaxTsdr_3M = 250
MaxTsdr_6M = 450
MaxTsdr_12M = 800
;
Redundancy = 0 ; redund. Transceiver not supp.
Repeater_Ctrl_Sig = 2 ; TTL
24V_Pins = 0 ; Not connected

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;
Implementation_Type = "SPC3"
Bitmap_Device = "DP_NORM"
;
; Slave-Specification:
Freeze_Mode_supp = 1 ; Freeze-Mode supported
Sync_Mode_supp = 1 ; Sync-Mode supported
Auto_Baud_supp = 1 ; auto. Baud. detec. supp.
Set_Slave_Add_supp = 0 ; Set_Slave_Add not supported
Min_Slave_Intervall = 10
;
Modular_Station = 1
Max_Module = 24
Max_Input_Len = 200
Max_Output_Len = 200
Max_Data_Len = 400
Modul_Offset = 200
;
Fail_Safe = 0 ; data telegram without data in
; ; state CLEAR not accepted
Slave_Family = 0
Max_Diag_Data_Len = 16
;
Unit_Diag_Bit(0) = "OK"
Unit_Diag_Bit(1) = "ERROR 1"
Unit_Diag_Bit(2) = "ERROR 2"
Unit_Diag_Bit(3) = "ERROR 3"
Unit_Diag_Bit(4) = "ERROR 4"
Unit_Diag_Bit(127) = "ERROR 127"
;
Module = "INPUT/OUTPUT: 1 Byte" 0x30
EndModule
Module = "INPUT/OUTPUT: 2 Byte " 0x70
EndModule
Module = "INPUT/OUTPUT: 4 Byte " 0x71
EndModule
Module = "INPUT/OUTPUT: 8 Byte" 0x73
EndModule
Module = "INPUT/OUTPUT: 16 Byte" 0x77
EndModule
Module = "INPUT/OUTPUT: 32 Byte" 0x7F
EndModule
Module = "INPUT/OUTPUT: 64 Byte" 0xC0,0x5F,0x5F
EndModule
Module = "INPUT: 1 Byte" 0x10
EndModule
Module = "INPUT: 2 Byte" 0x50
EndModule
Module = "INPUT: 4 Byte" 0x51
EndModule
Module = "INPUT: 8 Byte" 0x53

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857-VPA3CG Profibus DP Option Module
EndModule
Module = "INPUT: 16 Byte" 0x57
EndModule
Module = "INPUT: 32 Byte" 0x5F
EndModule
Module = "INPUT: 64 Byte" 0x40,0x5F
EndModule
Module = "INPUT: 128 Byte" 0x40,0x7F
EndModule
Dimensions
115 mm
(4.53 in.)
45 mm
(1.77 in.)
113 mm
(4.48 in.)

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857-VPA3CG Profibus DP Option Module
Specifications General
PROFIBUS Cable
PROFIBUS devices are connected in a bus structure. Up to 32 stations (master or
slaves) can be connected in one segment.
The bus is terminated by an active bus terminator at the beginning and end of
each segment (see Cabling Bus Termination on page 11). To ensure error-free
operation, both bus terminations must always be powered. When more than 32
stations are used, repeaters (line amplifiers) must be used to connect the
individual bus segments.
The maximum cable length depends on the transmission speed and cable type.
The specified cable length is increased by the use of repeaters. The use of more
than three repeaters in series is not recommended.
Table 2 - PROFIBUS DP Connections
Interface 9-pin DSUB connector (female)
Transfer method RS-485, Half-duplex
Transfer cable Twisted-pair (1 pair and shield)
Electrical 500V DC
Safety Meets standard EN50178
Table 3 - PROFIBUS Communication Data
Communication mode PROFIBUS DP
Communication parameters
Address 1…126
Baud Rate 9.6 kBaud...12 MBaud
Table 4 - Line Parameters
Parameter Line A Line B
Impedance 135...165 Ω (3…20 MHz) 100…130 Ω (f> 100 kHz)
Capacity < 20 pF/m < 60 pF/m
Resistance 110 Ω/km —
Wire gauge > 0.64 mm (22 AWG) > 0.53 mm (24 AWG)
Conductor area > 0.34 mm2 (22 AWG) > 0.22 mm2 (24 AWG)
Table 5 - Line Lengths for Different Transmission Speeds
Baud rate (bBit/s) 9.6 19.2 93.75 187.5 500 1500 3000…12,000
Length Line A (m) 1200 1200 1200 1000 400 200 100
Length Line B (m) 1200 1200 1200 600 200 — —