Endress+Hauser Profi Bus Levelflex M FMP40 Operating Instructions Manual page 52

Operation
52
IEEE-745 Floating Point Number
The measured value is transmitted as a IEEE 754 floating point number, whereby
VZ
Measured value = (-1) x 2
Byte 1
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3
7 6 5 4
VZ 2 2 2 2
Exponent (E)
Byte 3
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3
-8 -9 -10 -11 -12
2 2 2 2 2
Example:
40 F0 00 00 (hex) = 0100 0000 1111 0000 0000 0000 0000 0000 (bin)
0
= (-1)
= 1 x 2
= 1 x 4 x 1.875
= 7.5
Status codes
The status codes comprise one byte and have got the following meaning:
Status- Device status
Code
0C Hex BAD
0F Hex BAD
1F Hex BAD
40 Hex UNCERTAIN
47 Hex UNCERTAIN
4B Hex UNCERTAIN
4F Hex UNCERTAIN
5C Hex UNCERTAIN
80 Hex GOOD
84 Hex GOOD
89 Hex GOOD
8A Hex GOOD
8D Hex GOOD
8E Hex GOOD
If a status other than "GOOD" is sent to the device, the display indicates an error.
(E-127)
x (1+F)
Bit 2 Bit 1 Bit 0 Bit 7
3 2 1 0
2 2 2 2
Bit 2 Bit 1 Bit 0 Bit 7
-13 -14 -15 -16
2 2 2 2
Mantisse (F)
(129-127) -1 -2
x 2 x (1 + 2 + 2
2
x (1 + 0.5 + 0.25 + 0.125)
Significance
device error
device error
out-of-service (target mode)
non-specific (simulation)
last usable value
(Fail-safe-Mode aktiv)
Substitute set
(fail-Safe mode active)
initial value
(fail-Safe mode active)
Configuration error
(limits not set correctly)
OK
Active block alarm
(static revision counter incremented)
LOW_LIM (alarm active)
HI_LIM (alarm active)
LOW_LOW_LIM (alarm active)
HI_HI_LIM (alarm active)
Levelflex M FMP40 PROFIBUS PA
Byte 2
Bit 6 Bit 5 Bit 4 Bit 3 Bit 2
-1 -2 -3 -4 -5
2 2 2 2 2
Mantisse (F)
Byte 4
Bit 6 Bit 5 Bit 4 Bit 3 Bit 2
-17 -18 -19 -20 -21
2 2 2 2 2
-3
+ 2 )
Primary value
X
X
X
X
X
X
X
X
X
X
X
X
Bit 1 Bit 0
-6 -7
2 2
Bit 1 Bit 0
-22 -23
2 2
Secondary value
X
X
X
Endress+Hauser