BEKA BA488CF User manual

Issue : 4
24 June 2010
Profibus PA
Fieldbus Display [Revision 2 ]
and Fieldbus Indicator
Fieldbus Interface Guide

This guide applies to the following models:
Multiple Variable Fieldbus Display
BA488CF - Panel mounted, Intrinsically Safe
BA484DF - Field mounted, Intrinsically Safe
BA688CF - Panel mounted, Safe Area
BA684DF - Field mounted, Safe Area
Eight Variable Fieldbus Indicator
BA444DF - Field mounted, Intrinsically Safe
BA444NDF - Field mounted, Type nL
BA448CF - Panel mounted, Intrinsically Safe
BA644DF - Field mounted, Safe Area
BA648CF - Panel mounted, Safe Area
Please note: There are significant differences between Revision 2
Fieldbus Displays (those with version 3 firmware) and prior versions.
Documentation for these earlier products is available from our website,
or by contacting our sales department.
Can’t make it work ?
Please refer to the Troubleshooting section in Appendix B for common
problems and their solutions, and Appendix C for a worked example of setting
up the Listener.
If you still need assistance, please contact us directly:
Tel: [phone]
Email: [email protected]

Contents
Introduction ...................................................................................................................................................................... 4
What’s in this Fieldbus Interface Guide......................................................................................................................... 4
What’s in the Instruction Manuals .................................................................................................................................4
Other sources of information ......................................................................................................................................... 4
Displays Vs Indicators...................................................................................................................................................... 4
General Operation ............................................................................................................................................................ 5
Profibus Introduction ..................................................................................................................................................... 5
Configuration Methods .................................................................................................................................................. 8
Fieldbus Display : Product Overview ............................................................................................................................. 9
Display........................................................................................................................................................................... 9
Analogue Input Display ................................................................................................................................................. 9
Switch Inputs ................................................................................................................................................................. 9
Switch Outputs............................................................................................................................................................... 9
Profibus Block Structure................................................................................................................................................ 9
Profibus Configuration................................................................................................................................................... 9
Fieldbus Display : Features............................................................................................................................................ 10
Standard Screens.......................................................................................................................................................... 10
Setting the Fieldbus Address........................................................................................................................................ 11
Configuring the values to be displayed........................................................................................................................ 11
Configuring Units display and Tag information .......................................................................................................... 11
Reading the keypress status ......................................................................................................................................... 12
Controlling the (optional) alarm outputs...................................................................................................................... 12
Configuring alarm setpoints......................................................................................................................................... 12
Reading the approximate ambient temparture ............................................................................................................. 12
Fieldbus Indicator : Product Overview ........................................................................................................................ 13
Display......................................................................................................................................................................... 13
Analogue Input Display ............................................................................................................................................... 13
Switch Inputs ............................................................................................................................................................... 13
Switch Outputs............................................................................................................................................................. 13
Profibus Block Structure.............................................................................................................................................. 13
Profibus Configuration................................................................................................................................................. 13
Fieldbus Indicator : Features......................................................................................................................................... 14
Setting the Fieldbus Address........................................................................................................................................ 14
Configuring the values to be displayed........................................................................................................................ 14
Reading the keypress status ......................................................................................................................................... 14
Reading the approximate ambient temparture ............................................................................................................. 14
Appendix A Profibus PA Reference Information .................................................................................................... 15
Block Identifiers........................................................................................................................................................... 16
Data Types and Structures ........................................................................................................................................... 16
Floating Point Format .................................................................................................................................................. 19
Visible String Format................................................................................................................................................... 19
AO Transducer block – 488 Display............................................................................................................................ 20
AO Transducer block – 444 Indicator.......................................................................................................................... 21
DI Transducer block – 488 Display and 444 Indicator ................................................................................................ 22
Appendix B Troubleshooting....................................................................................................................................... 23
What version do I have? .............................................................................................................................................. 24
How do I reset it to Factory Defaults? ......................................................................................................................... 24
Why does the unit always display 0.0 BAD?............................................................................................................... 24
Appendix C Using a Profibus Listener Worked Example ....................................................................................... 25
Setting up the Profibus Listener................................................................................................................................... 26

4
Introduction
This guide gives all the necessary information to use our Fieldbus Displays and Indicators on a Profibus PA installation.
Several other protocols are commonly used in industry which we may choose to support as market demand rises. This
guide and others will periodically be updated, so please come back to our website regularly for the latest information.
For hardware installation information, please refer to the separate instruction manuals available for each model.
What’s in this Fieldbus Interface Guide
•An overview of each instrument
•Adescription of the parameters that are applicable to each instrument.
•Instructions on how to use the instrument in its standard modes
What’s in the Instruction Manuals
•An overview of the instrument
•Intrinsic Safety Certification information
•System Design and Installation
•Configuration
•Maintenance
Other sources of information
Our website at www.beka.co.uk is kept up to date with the latest literature and information
After reading through this guide, if you still have a problem getting the results you need then email us at
[e-mail] and we will do our best to help you
Displays Vs Indicators
The displays and indicators are internally very similar, but present the data in totally different ways. The simpler
Indicators have a non-backlit 5 digit, 7 segment display and 31 segment bargraph and are designed to give a cost
effective indication to operators. The more comprehensive Displays have a configurable backlit dot-matrix LCD, and
have provision for external pushbuttons and alarm outputs.
The Indicator is able to operate in a “Listener” mode whereby it does not appear as a device on the network, but simply
listens for appropriate data on the segment it is connected to. All configuration must be performed locally, but thereafter
it imposes no overhead on the network. This mode is useful where timing is critical, in retrofit applications or when
node licensing costs need to be minimised.
Both products can display up to eight variables, selectable by pushbuttons on the front of the instrument. In addition, the
pushbuttons can be used for operator feedback.

5General Information
General Operation
The primary purpose of a BEKA fieldbus display is to enable local indication of up to 8 fieldbus process variables.
This is normally achieved using cyclic data writes to the AO Function blocks.
The configuration of the display can be manually carried out using the local configuration menus, or acyclic data
transfers can be sent to parameters in the custom transducer blocks using DPV1 or DPV0 user prm data.
Profibus Introduction
Profibus is a fieldbus protocol designed for communicating between host and field devices. There are several layers to
the Profibus standard: Profibus DP (Decentralised Periphery) is the high speed solution designed and optimised
especially for communication between automation systems and decentralised field devices. Profibus DP exchanges
input and output information in a cyclic manner. This cyclic data traffic is the basis of the system and is described as
Version 0 or DPV0.
Atypical automation system will read all the inputs and then use this data in conjunction with the process design
parameters to calculate the new output values. These values will then be written to the output devices. The whole cycle
will then start all over again. This sequence is described as Cyclic Data.
The time cycle required to control the process on the plant often leaves the host with some spare time that can be used
for background and other tasks. This, combined with the need of the instrument engineer to be able to configure and
maintain the field devices without going out on to the plant, led to the development in 1997 of a revised standard,
Profibus DPV1.
DPV1 provides the host with a mechanism to get data about the configuration and health of each field device. This only
happens when specifically requested, and only when the host controller has the time to be able to do it. This kind of data
transfer is known as Acyclic data.
It is important to note that Cyclic Data traffic has priority over the Acyclic Data traffic as it is used for the plant control.
The following diagram shows how the data flows from the host to the BEKA Fieldbus device:
Read
Inputs
Other
Tasks
Process
Values
Write
Outputs

6General Information
Slot 14 OUT_D
Slot 9 OUT_D
Slot 1 Module n
Slot 8 Module n
Slot 14 – DI Function Block
Slot 9 – DI Function Block
Slot 1 – AO Function Block
Slot 8 – AO Function Block
Slot 0 – Physical Block
Slot 15 – AO Transducer Block
BEKA Fieldbus DisplayHOST Controller
Display
Application
Software
Host Application capable of dealing
with Profibus DPV1 extensions
e.g. Softing Configurator, Siemens
PDM or via an OPC Server
Data transfer is acyclic when the host
has time available.
14 Slots in
Profibus Host
System
Data transfer is
cyclic and routine
Slot x Module n Slot x – AO Function Block
Module 12345678Variable
Bytes Used 0 5 12 8 15 10 13 25
**** *Set point
* * * ReadBack
* * * Pos D
* * * * Checkback
***Rcas_In
***Rcas_Out
PROFIBUS DPV1 Area
PROFIBUS
DPV0 Area
Slot 16 – DI Transducer Block

7General Information
The BEKA Fieldbus Display is shown on the right side of the diagram. It consists of 17 virtual blocks named Slot 0 to
Slot 16. Data is transferred between the host and these slots by either routine cyclic data, or occasional acyclic data.
The resource block at Slot 0 gives the host a point of reference to find out about the facilities of the unit. This is only
done occasionally, so an acyclic data transfer is used for this purpose. The 8 AO function blocks at slots 1 – 8 are where
the host places the data to be displayed. The 6 DI function blocks at slots 9 – 14 are where the display places the keypad
information. As these are constantly being updated, routine cyclic data transfers are used. The remaining two transducer
blocks at slot 15-16 are used to configure the display, again by using (occasional) acyclic data.
The 8 AO function blocks are standard Profibus blocks, the specifications of which are available from the Profibus
organisation (As such the fine detail is not repeated in this manual). Each function block has 6 variables that can be
made accessible to the host system. These are shown in the first column of this table:-
Variable Module
1
Module
2
Module
3
Module
4
Module
5
Module
6
Module
7
Module
8
Set Point     
Readback   
POS D   
Checkback    
RCas_In   
RCas_Out   
Number of bytes
used in memory map 0 5 12 8 15 10 13 25
There are defined combinations of these 6 variables available as modules which are defined in the GSD description of
the BEKA device. These modules are used to selectively show or hide the variables that are relevant to the host
application. The choice of which module to use will depend on the design of the process and is left to the user to decide,
but for simple display applications the Set Point Module, Module 2 will be adequate.
When the Fieldbus Display is first loaded on the host system, the user will find 8 slots that can be configured with the 8
different types of module. If the user configures each slot with Module 2 then the host will only be able to access the
Setpoint on each function block. Each slot on the host will then take up 5 bytes of space thus defining the memory map
that the host is able to access. Writing to the Setpoint value will cause that value to be display on the field device.
From the memory map perspective, write a 32 bit float to the first four bytes of the slot, and write a GOOD status value
(128) to the status byte. The number will then appear on the screen.
Host Display
STATUS: 1byte (8 bit unsigned)
VALUE: 4byte (32bit) float
Address
However if the user needs the more complex functions of the AO Function block, other modules can be chosen, the
choice of which will affect the memory map of the instrument seen by the host
status
Slot 8
35
status
Slot 7
30
status
Slot 6
25
status
Slot 5
20
status
Slot 4
15
status
Slot 3
10
status
Slot 2
5
status
Slot 1 value
0
IN_8
IN_7
IN_6
IN_5
IN_4
IN_3
IN_2
IN_1
Single Variable Screen
Use the up and down arrow
keys to select the input
(IN_1 to IN_8) that is
displayed

8General Information
Configuration Methods
Configuration may be performed via either DPV1 or DPV0 user prm data. However, some items must be configured
using the local menus as described in the Instruction Manual. The following table summarises what method can be used
to configure each parameter.
Item Display Indicator
Menu DPV0DPV1 DPV0 DPV1
INDATA (1 to 8)
Bargraph Yes Yes
Bargraph Minimum Yes Yes Yes Yes Yes
Bargraph Maximum Yes Yes Yes Yes Yes
Display Format Yes Yes Yes Yes Yes
Zero_Offset YesYesYesYes Yes
Gain_Factor YesYesYesYes Yes
Descriptor YesNoYes
Units YesNoYes
Status Text Yes Yes Yes
Instrument Temperature No No Read Only No Read Only
Last Variable Yes Yes Yes Yes Yes
Optional Local Alarms Yes No No

9Fieldbus Display
Fieldbus Display : Product Overview
Adetailed overview of the instrument is given in the instruction manual for each product. This should be read before
implementing any system using these instruments. However it is useful to summarise the main features of the product
before attempting to design any controlling software application.
Display
The instrument display is organised as 120 pixels horizontally by 64 pixels vertically. Each pixel is 0.7mm square, the
size of which improves the contrast and hence the readability at greater distances.
The display is also backlit by an ultra-efficient green LED module which enables the screen to be viewed in all
conditions, from bright sunlight to total darkness.
Analogue Input Display
The primary purpose of this instrument is to display process variables that exist in a system. Eleven pre-programmed
screen layouts are available to display one, two, three, four or eight variables simultaneously. A total of eight (8)
variables can be accessed by using the front panel push buttons.
Switch Inputs
There are six push buttons on the front of the panel mounted instrument, and four on the field mounted instrument. Both
models have the option of overriding these with up to six external switches which can be sized and labelled to suit the
application.
Switch Outputs
As an optional accessory (available only at the time of ordering), there can be six switch outputs available. These are
totally isolated and can be energised or de-energised independently of each other. They can be driven by alarm set-point
values that can be assigned so that they operate automatically. Note that they are not intended to be used as
conventional Profibus Alarms and should be used for indication only. They are under the control of the local application
and are actioned on received values against stored setpoints. There is no communication of status across the fieldbus.
Profibus Block Structure
There are eight Analogue Output function blocks, one for each input value. In addition there are six Digital Input
function blocks, one assigned to each key. All data is transmitted using cyclic data.
Profibus Configuration
Configuration may be performed via either DPV1 or DPV0 user prm data. However, some items must be configured
using the local menus as described in the Instruction Manual. These are summarised in the table on page 8.

10 Fieldbus Display
Fieldbus Display : Features
The following sections describes how to use the features of the display. The relevant instruction manual for the
instrument being used must be read in conjunction with these notes, as the operation and description of the menu
structure is not detailed here.
Standard Screens
There are eleven standard screens available. They are capable of displaying a selection of up to eight process variables,
together with their units of measure and tag description. Once a screen format has been chosen, each input variable can
be brought into view by pressing the up and down arrow keys.
The screen format is selected by using the local configuration menu as described in the Instruction Manual. One of
eleven standard display formats can be selected as shown in the following table:
One
Variable
Two
Variables
Four
Variables
One
+
H-Bar
Two
+
H-Bars
One
+
V-Bar
Two
+
V-Bars
Three
+
V-Bars
Four
+
V-Bars
Eight
Variables
Eight
+
Bars