FieldServer FS-8700-64 - Manual (Page 10)

FS-8700-64 ATMI ACM Page 9 of 22
FieldServer Technologies 1991 Tarob Court Milpitas, California 95035 USA Web:www.fieldserver.com
Tel: (408) 262-2299 Fax: (408) 262-9042 Toll_Free: 888-509-1970 email: [email protected]
4.4.5 Map Descriptor Example2 – Gas values for the current (most recent) port sample.
This example illustrates a map descriptors used to store the data from the most recent port sample. The map descriptor stores the following
information :-
1. Port Number
2. Up to 16 gas values (The gas name is not provided) The position in the array is based on the Gas Number.
For example. A port may sample two gasses. The first is Gas #4 and the second may be Gas #2, The driver stores the value of Gas#4 in
array location 4 and stores the value of Gas#2 at array location 2.
The following additional information may also be stored if the DA_Bit_Name & DA_Byte_Name parameters are specified.
3. A bit indicating the number of the port
4. The Alarm/Warning States for each gas
Map_blocks
Map_block_Name, Data_Array_Name, Data_Array_Offset, Function, node_name, protocol, timeout, atmi_data , da_bit_name, da_byte_name
Current_Port_MD, DA_CURR_PORT, 0 , passive , ACM1 , ATMI ,120.0s , current-port, DA_PORT , DA_PORT_ALA
The current port
number and up to 16
gas values are stored
in this data array.
The 1
st element
stored is the port
number. The next
16 values stored are
the gas values
(multiplied by 100).
The location is
based on the Gas
Number and not the
row number.
If x is the number of the current
port (port most recently
sampled) then the data array
position corresponding to x is
set to 1 and all other elements
are set to zero.
E.g. If Port 1 is the current port
then the 2
nd element of the
array (index=1) is set non-zero.
The array can be any data
format.
If the DA_Bit_Name parameter
is omitted then this data is not
stored.
This keyword tells
the driver to use this
map descriptor to
store the current
port’s sample data.. Alarm / Warning Status for each gas is
indicated in this array.
If gas x is in alarm then x is used as the
index into the array. E.g. If Gas #1 is in
alarm then the 2
nd element of the array
(index=1) is set non-zero.
The value of each element indicates
alarm/warning. If the Value is 1 then the
gas in alarm. If the value is two then the
gas is at a warning level.
The array format should be capable of
storing a value. If a Bit/Packed_Bit format
is used then you will not be able to
distinguish between an alarm/warning.
If the DA_Byte_Name parameter is
omitted then this data is not stored.