FS-8700-103_ATMI_TGM_Serial
Manual
Page
17
of
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Appendix B.2. How Gas Data is Stored
•
The QLA reports provides Gas Concentration values for each configured port/sensor
connected to the TGM.
•
The driver stores the data using the “Data_Array_Name” and “Data_Array_Offset”
parameters specified on the Map Descriptor. Two additional Data Array’s can be
specified to tell the driver where to store the gas names and egineering units.
•
The position at which data is stored in the array is deprendent on the TGM port/sensor
number. Use the following formula to determine the position.
For Port x : Relative Offset = Port_Number * 10
For Sensor x : Relative Offset = 200 + ( Sensor_Number * 10 )
•
Thus enough room is provided to store data from 20 ports and provided the Array is long
enough, there is no limit to the maxium sensor number.
•
The offset’s described here are relative to the offset provided in the Map Descriptor,
which should be added to the offsets specified here
Relative
Offset
Contents
In the Data Array specified by the “Data_Array_Name”
0 Port
Number
1
Set to 'P' for a port. Set to 'S' for a sensor
2
Gas concentration Value. Can be scaled by applying Map Desc scaling using
the parameters Data_Array_Low_Scale, Data_Array_High_Scale,
Node_Low_Scale, Node_High_Scale
3
Gas Conc. Engineering Units as an index value. Stores –1 if units are not
recognized. Index value is based on lookup table - Appendix A.3
4
Gas Status.
0=Normal; 1=Warn; 2=Alarm; 4=Error
5
Gas Name index (based on CALR report)
A list of gas names and index values is built when the CALR report is parsed. It
is not possible to provide a list of index values vs gas names in advance
because this is dependent on the TGM configuration.
To facilitate debugging your application the driver stores the list it builds in a
Data Array which can be read by an upstream device or which can be seen by
uisng the Ruinet Utility.
If the gas name is not recognized then the driver stores a value of –1.
6
Gas Name index based on looking up the gas name in the table provided in
Appendix A.1
If the gas name is not recognized by the lookup then a value of –1 is stored.
In the Data Array specified by the “DA_Bit_Name”
0
Gas Name is stored character for character to a max of 9 characters.
The name of the Map Desc parameter is confusing. The Data Array specified
with this parameter can have any format - ‘BYTE’ format is reccomended.
In the Data Array specified by the “DA_Byte_Name”
0
Gas Concentration Engineering Units are stored character for character to a
max of 9 characters.
The name of the Map Desc parameter is confusing. The Data Array specified
with this parameter can have any format and in fact the ‘BYTE’ format is
reccomended.
