Serial Output; Data Format; Markers - Bartington Grad601 Operation Manual

2 Position in the Y
direction in metres.
The Y direction
represents the spacing
between traverses.
3 Z, the gradient
measured in nT at that
point

20. Serial Output

The DL601 Data Logger outputs the data from memory via a three-line RS-232 interface (TX, RX
and Gnd). When Output data is selected from the main menu, the data logger will turn on the RS-
232 interface and wait until the character S is received from the PC before starting transmission.
The gradiometer will then transmit 32 signed integers as 64 bytes and wait for the next character
S from the PC.
The baud rate is set to 9600 baud with 8 data bits, no parity, 1 stop bit and no handshaking. The
last transmission may be less than 64 bytes.

20.1. Data Format

The data represents a number of Grids. The data file for each Grid comprises a header, the
gradiometer readings and summary information. An End of Transmission integer and a
final checksum follows the data for the final Grid. All data is saved in the gradiometer and
subsequently output in binary (signed integer) format, 2 bytes per integer, MSB first. All data is
translated into ASCII characters in the PC after receipt.
The gradiometer has ranges of ±100nT and ±1000nT denoted by values of 1 and 10 respectively
in the header information. Data is transmitted as signed integers in the range ±10,000,
representing values of ±100.00nT for the ±100nT range and ±1,000.0nT for the ±1000nT range.
The download software inserts the decimal point at the appropriate place. Integers above 32000
are used for markers in the data stream.

20.2. Markers

The following specific integers are reserved for markers.
BARTINGTON INSTRUMENTS
So that the plotted values correspond with the
spreadsheet view, the first traverse represents the
maximum value of Y and the last traverse corresponds
to the minimum value of Y.
Assuming the first traverse starts at the top left of the
Grid then
X=min, Y=min
left of the Grid;
and X=max, Y=max
n/a
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therefore represents the bottom
represents the top left;
X=min, Y=max
represents the top right.
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