Split Values; Text Messages - Siemens PROFIBUS DP-V1 Operating Instructions Manual

For example, when reading words 7 and 8, the 32 bits would look as follows:
15
31
The whole is read as a 32-bit integer.

Split values

Two parameters may sometimes be combined, forming one value. This pair of numbers is
presented as xx:yy. An example is Echo Confidence as shown in Measurement View 2
(see The LCD Display section of your Siemens device operating instructions). In this case,
a pair of 8-bit unsigned integers are viewed as a single value.
xx = the average noise value in dB
yy = the peak noise in dB
The number which corresponds to xx:yy, either for reading or setting a parameter, is
determined by the following formula:
For storing to the device:
value = (xx + 128) x 256 + (yy + 128)
For reading from the device:
xx
yy
where % is the modulus operator.
The modulus can be computed by following these steps:
value
1
value
2
value
3
yy = value
It may simplify parameter to notice:
xx = (most significant byte of value) – 128
yy = (least significant byte of value) – 128

Text messages

Note:
Used for Level products only
If a device parameter returns a text message, that message is converted to an integer
and provided in the register. The numbers are shown in the following table
Number
22222
30000
30001
30002
30003
A5E36197302
word 7
MSW
32-bit integer value (UINT32)
= (value / 256) – 128
= (value % 256) – 128
= value / 256
= remainder of value
1
= value x 256
2
– 128
3
Text message
Invalid value
OFF
ON
Parameter values of multiple points do not match.
Parameter does not exist.
SmartLinx PROFIBUS DP-V1 – Operating Instructions
0 15
word 8
LSW 0
0
Page 21