FieldServer FS-8700-123 Computer Drive User Manual


 
FS-8700-123 MetOne Particle Counter Serial Driver Manual Page 15 of 26
FieldServer Technologies 1991 Tarob Court Milpitas, California 95035 USA Web:www.fieldServer.com
Tel: 408 262-2299 Fax: 408-262-2269 Toll_Free: 888-509-1970 email: support@fieldServer.com
4.11. Map Descriptor Example 7 – Read the Current Record
In this example the driver reads the current record and stores the values in the specified Data Array. A single record comprises the
following data: status; date and time and a count for 1 or more locations. The driver has no advance knowledge of the number of
count fields to expect in the response. It simply stores them in consecutive locations in the Data Arrays. To map these counts to an
upstream protocol, the order of the count fields must be known. The driver can store a maximum of 20 count fields. The Map
Descriptor length must be set to a value that allows for enough data to be stored bearing in mind that it requires 8 DA elements to
store the status, date and time and period.
One of these Map Descriptors is required for each device from which the current record is to be read..
// Client Side Map Descriptors
Map_Descriptors
Map_Descriptor_Name, Data_Array_Name, Data_Array_Offset, Function, Node_Name Met1_Function, Length, Scan_Interval
Read Record, DA_DATA, 0, Rdbc, MET1, Current Record, 20, 1.0s
The length must be set to a
value large enough to store
the 8 fixed data items and
the variable number of count
fields.
Driver stores the current record information in the Data Array
specified here, starting at the specified offset. The data is
arranged as follows.
0
Status Byte
1
Date - Month
2
Date - Day
3
Date - Year
4
Time - Hours
5
Time - Minutes
6
Time - Seconds
7
Period
8
Count #1
9
Count #2
10
Count #3 …