67
Byte 103-110 (8 bytes IEEE Float, sign bit, 11-bit exponent, 52-bit mantissa)
: contact resistance
Byte 111-118(Unsigned Integer):
Contact resistance measurement time in seconds from
00::00::00 of 1/1/1970
3)
Record Block
Record Tag sub-block
Byte 0-1(unsigned integer)
: Each record block starts with Record ID, 5354H, which identifiers the
start of a record.
Byte 2-3(unsigned integer)
: record tag size in byte which is 45 at current time.
Byte 4-5(unsigned integer)
: transmitter No for the record.
Byte 6-7(unsigned integer)
: Number of channel in the record.
Byte 8(unsigned integer)
: Enable flag for the record. 0- disabled, 1-enabled;
Byte 9-12(unsigned integer)
: Bytes of free format string for the record.
Byte 13-20(Unsigned Integer):
Record time in seconds from 00::00::00 of 1/1/1970
Byte 21-28 (8 bytes IEEE Float, sign bit, 11-bit exponent, 52-bit mantissa)
: Sample rate in Hz
Byte 29-32(unsigned integer)
: Samples per channel.
Byte 33-36 (4 bytes IEEE Float, sign bit, 8-bit exponent, 23-bit mantissa)
: Signal frequency in Hz
Byte 37-40(unsigned integer)
: Number of stacks in the record.
Byte 41-44(unsigned integer)
: Transmitter divisor based Tx clock frequency of 4,980,736 Hz;
To make file flexible to add new parameters during development, I use free format strings to
store some parameters after each record tag. The string size in bytes is specified in
Byte 9-12
as
mentioned above. Each item is
keyword
and
value
string pair. There is no embedded white
space in the keyword but values do have this restriction. A white space is the separator between
keyword and value string.
Keyword
and
value
string pairs are separated by a NULL character.
Below are free string keywords at this moment (5/18/2016). But it could be modified in the
future if necessary.
CHNO: Channel number sequence in seg2 file. The channel number is separated by “_”, i.e. 1-2-
5-6
CHDEF: Channel definition sequence. The channel number is separated by “_”, i.e. Ey1-Ex1-Hx1-
Hy1
SKEW: Channel skew sequence. The channel number is separated by “_”, i.e. 0.0001-0.0004-
0.4444 -0.22222
(4 bytes IEEE Float sign bit, 8-bit exponent, 23-bit mantissa
Record data sub-block
