ProSoft Technology PS-QS-1x10-0781 - Manual (Page 21)

FieldServer Configuration Manual Page 21 of 90
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5.1.1 Simple Moves
The simplest move involves the transfer of data without any format or protocol changes. Whenever the Source
Data Array is updated (not necessarily changed) the Target Data Array will be updated.
5.1.1.1 Simple Move Example
Data_Arrays
Data_Array_Name , Data_Format , Data_Array_Length
Source_DA
, Float , 200
Target_DA , Float , 200
Moves
Function , Source_Data_Array , Source_Offset , Target_Data_Array , Target_Offset , Length
Move_Only , Source_DA , 0 , Target_DA , 40 , 5
5.1.1.2 Special Application: Grouping Data
The location of data in Data Arrays on the FieldServer is determined by corresponding Map Descriptors. Should a
Client poll the FieldServer for data spanning more than one Map Descriptor, the FieldServer will not know which
Map Descriptor to use. This can be circumvented by moving data from multiple “Client Side” Source Data Arrays to
a single “Server Side” Target Data Array. This Data Array should be larger (of greater length) than the maximum
poll length of the Client.
Example
Consider a Modbus Client needing registers 40001 through 40050 from the FieldServer. The poll lengths used to
obtain this data are unknown.
This could be configured in the FieldServer Server side as follows:
Configuration 1: Map Descriptor 1 serves up 40001 Length 25 :
Map Descriptor 2 serves up 40026 Length 25
Client side Data Array 1
Client side Data Array 4
Client side Data Array 2
Client side Data Array 3
Server Side Data
Array
Remote Client can
now poll the
FieldServer using
large poll lengths
without fear of
hitting undefined
registers.
One Server
Data Array
means One
Server Map
Descriptor is
possible
Five Floating point values are
moved from the first offset of
Source_DA to Offset 40 of
Target DA
Move is reversible, meaning
data can move from
Target_DA to Source_DA if
applicable (writeable points