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D OW N L OA D I N G DATA O N M E A S U R E
CAMPAIGNS STORED IN INTERNAL MEMORY
The downloading of recorded data takes place
through Modbus commands:
- Command for request of number of records
memorized;
- Command for request of number of records starting
with number m.
Using the Modbus protocol for data request made
it necessary to assign the reading command with
a range of virtual addresses that would simulate
the data request from memory; specifically, the
address 0x4000 was assigned to the request for
the number of records stored, whereas the range
of addresses of records stored ranges from 0x8000
to 0xEE40; which are the 28224 max records that
can be stored. The transmission takes place only
at 8 bits; up to 7 records can be transmitted through
a Modbus command.
Format of the request string:
“:0103 4000 0001 3B” + cr lf
Request of number of records stored
“:0103 xxxx yyyy LL” + cr lf
Request of yyyy records starting from number xxxx;
“:0105 0006 0000 F4” + cr lf Set UART 8 bit
“:0105 0007 0000 F3” + cr lf Reset UART
Given that the test on the reception of a Modbus
command by the NANOVIP PLUS MEM takes place
when the calculation is finished, there would be the
transmission of each record block requested
approximately every second, which is the time
NANOVIP PLUS MEM takes to perform the measure.
To accelerate the total downloading of the memory,
as soon as the first data request is made you do
not return immediately to performing the next
measure, but “listen” for a set amount time to the
serial to receive the next command for downloading
data. When entering the maximum transmission
speed at 38400 baud, the maximum time for
downloading all the memories completely (1
Megabyte) is 15 minutes.
Format of transmitted data:
Response string for request of number of records
stored:
“:0103 01 xxxx LL” + cr lf
xxxx represents the number of records stored
Response string for n record request :
“:0103 nn
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AABBBBBBBBBBBBBBBBBBBBBBBBB… LL”
+ cr lf
- nn represents the number of words transmitted
- A max. of 7 records of 32 bytes follow; these are
the records requested starting with the first one.
The format of the string transmitted by the NANOVIP
PLUS MEM is not pure Modbus ASCII as that of
the other strings; the max. 7 records are in an 8 bits
binary format, not 7 bits ASCII, so the Uart must be
set at 8 bits with the special command before making
the transmission, then the setting restored with a
further command.
ENGLISH
