Santec MPM-210H - Page 48

MPM-210H OPERATION MANUAL
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bytes.)
4
Measuring
data
BINARY
Send measuring data.
(Note: Send 4-byte data through 4 times and 1
byte at each time by dividing a number in
floating point format as above. Send 4-byte data
in order of LSB to MSB four times and 1 byte at
each time.)
Example 1) Sending 100 measuring data
In case 100 numbers in floating point format are sent, single precision floating
point data is transferred as four bytes data every on byte. If the whole data is
converted into bytes, it is 400 bytes long.
Table 5.6.1 Example of binary data transmission
Table 5.6 1 shows the order of transmission when MPM-210H sends 100
measuring data to PC. In GPIB and TCP/IP, communication data is sent in the
same way as in Table 5.6.1.
Binary data format used in MPM-210H is IEEE Standard Floating Point Format
as in Table 5.6.2. (Note: Binary data is sent every 8 bit from least significant
byte to most significant byte.)
Table 5.6.2 Floating Point Data Structure
Name
Sign bit
Exponent bit
Fraction bit
Symbol
S
E
F
Bit
31(MSB)
30 ~ 23
22 ~ 0(LSB)
Sign bit is the 31
st
bit. ‘0’ means a positive number and ‘1’ means negative
number. Exponent is composed of 8 bits from the 30
th
bit to the 23
rd
one, and it
can express a number between 0~255. The median of Exponents is 127. If
Exponent is larger than 127 it is positive, and if it is smaller than 127 it is
negative. That is, 127 means 2
0
, 128 2
1
and 126 2
-1
. Fraction indicates a
decimal below 1. The 22
nd
bit is the decimal number of 1/2, the 21
st
bit the
Order of
transmission
1
2
3
4
5
6
7
8
….
405
Data format
ASCII
ASCII
ASCII
ASCII
ASCII
BINARY
BINARY
BINARY
….
BINARY
Receiving
#
3
4
0
0
1byte
1byte
1byte
….
1byte