Omega DP41-B Series User Manual page 77

10. Data Format Commands (P, G, R, W)
10.34 READING, INPUT, or OUTPUT SCALE FACTOR continued
The most significant nibble of the scale factor data sets the decimal point (power of 10
multiplier) for the least-significant nineteen bits, which give the magnitude using a right-
hand decimal point (decimal 499,999 full scale). The bit in between, #19, is the sign
bit, "0" for "+" and "1" for "-", which is OR'd with the magnitude to get the HEX value of
the second nibble. The decimal-point code is given in Table 10.28. The figure "4"
indicates the maximum value in that position and "x" is any chosen decimal digit.
Bit pattern information is as follows:
1) Bits 0 to 18 belong to the absolute value.
2) Bits 20, 21, 22, 23, belong to decimal point as shown in Table 10.28.
3) Bit number 19 belongs to the sign and is "0" for positive and "1" for negative.
TABLE 10.28. READING SCALE ("RdG SC"), INPUT SCALE ("INP SC"), AND
OUTPUT SCALE ("OUt SC") BITS 23, 22, 21 AND 20
BIT NUMBER
23 22
0 0
0 0
1 0
0 0
0 1
0 1
0 1
0 1
1 0
1 0
1 0
1 0
1 1
1 1
1 1
1 1
EXAMPLE: Desired reading scale factor is 123.45. The magnitude is 12345, which is
hex 03039. The polarity is negative, so the 19th bit is a "1", giving hex "80000"; when
OR'2 with the magnitude, the least-significant 5 nibbles are hex "83039".
The decimal-point is two places to the left of the right-hand position (e.g., of the 6-digit
display). The decimal point is thus -2, which is a MSB of 3 from the Table 10-28.
OR'd with the other 5 nibbles, hex "383039", write this factor to the EEPROM of meter
hex #15 with: *15W08383039<CR>. The meter will echo 15W08<CR> if you have set
"BUS.FMt".
DECIMAL
21 20 NUMBER
0 0 4xxxxx0.
0 1 4xxxxx.0
1 0 4xxxx.x0
1 1 4xxx.xx0
0 0 4xx.xxx0
0 1 4x.xxxx0
1 0 4.xxxxx0
1 1 .4xxxxx0
0 0 .04xxxxx0
0 1 .004xxxxx0
1 0 .0004xxxxx0
1 1 .00004xxxxx0
0 0 .000004xxxxx0
0 1 .0000004xxxxx0
1 0 .00000004xxxxx0
1 1 .000000004xxxxx0
10-30
POWER OF10
MULTIPLIER
1
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
-11
-12
-13
-14