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A Sierra Monitor Company
Driver Manual
(Supplement to the FieldServer Instruction Manual)
FS-8700-115 General Purpose ASCII
APPLICABILITY & EFFECTIVITY
Effective for all systems manufactured after May 1, 2001
Driver Version:
1.00
Document Revision: 4
FS-8705-06 GPA (General Purpose ASCII) Manual
Page 3 of 15
1.
GPA (General Purpose ASCII) Driver Description
The serial GPA (General Purpose ASCII) Driver allows the FieldServer to accept data from
remote devices which produce an ASCII byte stream. A typical example of such a device is an
electronic scale producing an output similar to the one below.
:weight 0.57 Kg Tare 44.3 Kg 1 2 3 4 -5 -6.7
The driver waits passively for messages. When a message is received the driver converts each
space delimited string of characters/numbers into a number. The numbers so formed are stored
in consecutive elements of a Data Array. Referring to the example above, the driver will store
the value .57 in the 1st element of the Data Array (DA), the value 44.3 in the next element, the
value 1 in the next, the value 2 in the next etc.
The driver can process negative numbers.
This driver has significant limitations:
Only one data stream per connection - if two different streams of string data are sent to the
same port, the data from the one will overwrite data from the other.
The driver can only process numbers that are presented in a simple numeric form.
Hexadecimal, Exponent-mantissa and other complex forms cannot be processed.
Max Nodes Supported
FieldServer Mode
Client
Server
Nodes
1
Comments
Only 1 node per port.
The driver cannot serve data
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2.
Driver Scope of Supply
2.1. Supplied by FieldServer Technologies for this driver
FieldServer Technologies
PART #
Description
FS-8915-10
FS-8915-10
FS-8917-02
FS-8917-01
UTP cable (7 foot) for Ethernet connection
UTP cable (7 foot) for RS-232 use
RJ45 to DB9F connector adapter
RJ45 to DB25M connection adapter
Driver Manual.
FS-8705-96
2.2.
2.2.1.
Provided by the Supplier of 3rd Party Equipment
Required 3rd Party Hardware
Part #
Description
None
2.2.2.
Required 3rd Party Configuration
Consult your vendor documentation. It is not possible to provide direction here as this
driver can be connected to a huge range of devices.
FS-8705-06 GPA (General Purpose ASCII) Manual
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3.
Hardware Connections
The FieldServer is connected to the vendor device as shown in connection drawing.
Configure the ASCII Passive Client according to manufacturer’s instructions
Ethernet Network
Connection via std networking
interfaces such as hubs, switches,
routers.
Use 8917-02 or a 3 wire cable
where you connect the remote
device Xmit to RJ45-01, the remote
Receive to RJ45-08 and, the gound
wire to RJ45-04.
ASCII Data
Source
Eg. Scale
FS-8705-06 GPA (General Purpose ASCII) Manual
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4.
Configuring the FieldServer as an GPA Driver Client
For a detailed discussion on FieldServer configuration, please refer to the FieldServer
Configuration Manual. The information that follows describes how to expand upon the factory
defaults provided in the configuration files included with the FieldServer (See “.csv” sample files
provided with the FieldServer).
This section documents and describes the parameters necessary for configuring the FieldServer
to communicate with a GPA (General Purpose ASCII) Driver Server.
4.1.
Data Arrays/Descriptors
The configuration file tells the FieldServer about its interfaces, and the routing of data
required. In order to enable the FieldServer for GPA (General Purpose ASCII) Driver
communications, the driver independent FieldServer buffers need to be declared in the
“Data Arrays” section, the destination device addresses need to be declared in the “Client
Side Nodes” section, and the data required from the servers needs to be mapped in the
“Client Side Map Descriptors” section. Details on how to do this can be found below.
Note that in the tables, * indicates an optional parameter, with the bold legal value being the
default.
Section Title
Data_Arrays
Column Title
Function
Legal Values
Up to 15 alphanumeric
characters
Data_Array_Name
Provide name for Data Array
Float, Bit, UInt16, SInt16,
Provide data format. Each Data Packed_Bit,
Byte,
Data_Array_Format
Data_Array_Length
Array can only take on one format.
Packed_Byte,
Swapped_Byte
Number of Data Objects. Must be
larger than the data storage area
required by the Map Descriptors for
the data being placed in this array.
1-10,000
Example
// Data Arrays
Data_Arrays
Data_Array_Name,
DA_AI_01,
DA_AO_01,
DA_DI_01,
Data_Array_Format,
Data_Array_Length
UInt16,
UInt16,
Bit,
200
200
200
200
DA_DO_01,
Bit,
FS-8705-06 GPA (General Purpose ASCII) Manual
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4.2.
Client Side Connection Descriptions
Section Title
Connections
Column Title
Function
Specify which port the device is connected
to the FieldServer
Legal Values
P1-P8, R1-R21
Port
Protocol
Baud*
Specify protocol used
ASCII
110
baud rates only
Even, Odd, None, Mark,
Space
–
115200, standard
Specify baud rate
Specify parity
Parity*
Data_Bits*
Stop_Bits*
Specify data bits
Specify stop bits
7, 8
1
Handshaking* Specify hardware handshaking
RTS, RTS/CTS, None
Example
//
Client Side Connections
Connections
Port,
P8,
Protocol,
ASCII,
Baud,
9600,
Parity,
None,
1
Not all ports shown are necessarily supported by the hardware. Consult the appropriate Instruction
manual for details of the ports available on specific hardware.
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4.3.
Client Side Node Descriptors
Section Title
Nodes
Column Title
Node_Name
Function
Provide name for node
Legal Values
Up to 32 alphanumeric characters
This commonly used node
descriptor parameter has no
special meaning for this driver.
Incoming messages could come
from any node.
Node_ID
A Node_ID may be allocated and
any value may be used
Protocol
Specify protocol used
ASCII.
Specify which port the device is
connected to the FieldServer
Connection
P1-P8, R1-R22
Example
// Client Side Nodes
Nodes
Node_Name,
PLC 1,
Node_ID,
1,
Protocol,
ASCII,
Connection
P8
2
Not all ports shown are necessarily supported by the hardware. Consult the appropriate Instruction
manual for details of the ports available on specific hardware.
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4.4.
4.4.1.
Client Side Map Descriptors
Column Title
FieldServer Related Map Descriptor Parameters
Function
Legal Values
Up
to
32
Map_Descriptor_Name Name of this Map Descriptor
alphanumeric
characters
One of the Data
Name of Data Array where data is to be Array names from
Data_Array_Name
Data_Array_Offset
stored in the FieldServer
“Data
Array”
section above
0
to
maximum
specified in “Data
Starting location in Data Array
Array”
above
section
Function of Client Map Descriptor.
Refer to the FieldServer configuration
information for more information. Note
that passive client means that the map
descriptor owns the Data Array
elements and no other active Map
Descriptor can address the same data.
Function
Server, passive
4.4.2.
Driver Related Map Descriptor Parameters
Function
Column
Title
Legal Values
One of the node names
specified in “Client Node
Descriptor” above
Node_Name Name of Node to fetch data from
Data type
Your choice affects how data is stored.
Ana_Input , Ana_Output ,
If you use a Digital type then data is
Data_Type
Register
, Float_Reg ,
stored only as 1’s or Zero’s. If you use
non Float types the values are truncated.
Thus 0.6 is stored as zero.
Dig_Input , Dig_Output
Length of Map Descriptor
Specifies the maximum number of string
items that can be converted to numbers
Length
and stored.
1,2,3…
Other than ‘using up’ point count, there is
no danger in setting the length to a larger
number than required.
This commonly used parameter is not
used by this driver.
Address
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4.5.
Map Descriptor Example.
In this example, we provide a map descriptor to capture data from a scale and store it in a Data Array called ‘DA_Scale’. The 1st
element converted from the ASCII steam will be store at offset zero in the Data Array. The driver will convert and store floating point
numbers because the data_type is a floating point type. A maximum of 10 number fields can be processed and stored. The driver
only converts and stores the data when the ASCII stream ends. Read appendix xxxxxx to learn how the driver knows when a stream
has ended and it should process and strore data.
Map_Descriptors
Map_Descriptor_Name,
Store_Weights,
Data_Array_Name,
DA_Scale,
Data_Array_Offset,
0,
Function,
Passive,
Node_name
Node_A,
Data_Type
Float-Reg
Length
10,
Driver waits passively
for incoming data.
There is no polling.
Connects this Map
Descriptor to a Node
Descriptor which in
A maximum of
10 value items
will be stored.
The name of the
Data Array where
the incoming data
should be stored.
Map
Descriptor
Names do not
need to be unique
but making them
so may facilitate
trouble shooting.
turn points to
a
When the driver processes the
stream it should (in this case) treat
the data as floating point data.
Ensure that the format of the Data is
suitable to store a floating point
value
connection descriptor.
The 1st element of
converted data will be
stored at this location
in the DA. Subsequent
data is stored in
consecutive locations.
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5.
Configuring the FieldServer as a GPA Driver Server
Driver cannot be used to serve data. Contact the Sales group at FST if you are interested in
this functionality.
FS-8705-06 GPA (General Purpose ASCII) Manual
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Appendix A. Advanced Topics
Appendix A.1. Separating Data Streams.
The driver processes the ASCII stream and stores the converted data when the stream
ends. By default the driver closes the stream when it receives the CR character (Hex code
= 0x0d Decimal code = 13).
The default end of stream character can be changed using the registry.
The example below is an extract from registry.ini. The Registry group is for port P1. Similar
groups can exist for other ports and a group may have more settings than those shown
below. If you wished to change the end of stream character to a NEW LINE character
(Hex=0x0a Decimal=10) then change the 13’s to 10’s in the example below. The default_
value is used by the registry when it receives a ‘restore defaults’ command.
[FieldServer_P1]
Termination_Char = 13
default_Termination_Char = 13
Appendix A.2. Interaction with the WebServer Driver
This driver is specially configured to watch for registry changes that are initiated from the
WebServer driver. It is possible to configure the connection settings of the port without
changing the configuration file as follows:
•
•
•
•
Create web pages to change the registry settings.
Browse to the web page.
Change a setting.
When the WebServer sees that the new settings have been updated it sets a signal for
the ASCII driver to use the new settings.
The html fragment below can be inserted in a Web Page. It will allow a user via a browser to
change the connection settings for P1.
<FST_COMBO
Reg_name
=
"FieldServer_P1:Baud"
List_Items="300;600;1200;2400;4800;9600;19200;38400;115200;">
<FST_TEXT Reg_name = "FieldServer_P1:Data_Bits" >
<FST_TEXT Reg_name = "FieldServer_P1:Stop_Bits" >
<FST_TEXT Reg_name = "FieldServer_P1:Parity" >
You can add a similar field for any parameter in the registry file but note that only some
registry settings are used by this driver and only some drivers (including this one) are
designed to be notified of a change and will work with the changed data.
Using this interface you can deliver a system which a customer can simply use to adjust the
connection settings without learning how to configure a FieldServer. Ensure that registry.ini
is installed on the FieldServer.
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Appendix B. Troubleshooting tips
Appendix B.1. Timeouts
If the end of stream character has not been received in the default timeout period of 0.5
seconds the driver clears the incoming buffer and waits for the beginning of the next stream.
FS-8705-06 GPA (General Purpose ASCII) Manual
Appendix C. Driver Error Messages
Page 14 of 15
Error
Description and Corrective Action
ASCII:#1
\"%s\"
FYI.
Port
Connection You can safely ignore this message. It is designed to make you
Parameters Can Be aware of the capability of the driver. Refer to Appendix A.2
Changed Remotely
You can safely ignore this message if the setting reported match
ASCII:#2a/b FYI. Port
your expectations. The driver is reporting that connection settings
\"%s\" Setting Changed
have been changed. The change resulted from a change to the
Remotely. New Setting:
FieldServer registry settings and this driver has been notified to start
%s
working with the new settings.
ASCII:#3a/b FYI. Port
The driver is reporting initial settings for port. The message is for
\"%s\" Initial Setting:%s
your information only and no corrective action is required if it
Start Char 0x%2X
confirms you expectations. If it doesn’t review and correct the
configuration file or registry.ini file.
End
Char
0x%02X
Termination Time %fs
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