ProSoft Technology PS-QS-1x10-0781 - Manual (Page 26)

FieldServer Configuration Manual Page 26 of 90
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Moves
Function , Source_Data_Array , Source_Offset , Target_Data_Array , Target_Offset , Length
Bit_Pack , Source_DA
, 10 , Target_DA , 2 , 12
5.2.6 Example 3 - Extracting bit groups
The following example extracts 3 bits from the second byte of a 32-bit register and places them into a byte register
on their own. The Bit_Offset keyword is used here to achieve this:
Data_Arrays
Data_Array_Name , Data_Format , Data_Array_Length
Source_DA
, Uint32 , 200
Target_DA , Byte , 200
Moves
Function , Source_Data_Array , Source_Offset , Bit_Offset , Target_Data_Array , Target_Offset , Length
Bit_Move , Source_DA , 0 , 8 , Target_DA , 0 , 3
5.2.7 Bit Extraction – Application Example
Assume a Liebert device has been set up as follows:
Liebert UPS (MM4)
Alarm String I - Modbus Register: 40289
Bit Description Bit Value
0 Communications 1
1 Battery Discharge 2
2 Input Failure 4
3 Hardware Shutdown 8
4 DC Ground Fault 16
5 Input CB Open 32
6 Output CB Open 64
7 DC Cap Fuse Blown 128
8 Low Battery Reserve 256
9 Output Overload 512
10 Rectifier Fuse Blown 1024
11-15 Unused
Bits 0 - 10 are each used to specify a unique event, and each has a corresponding integer value determined by the
binary contribution it makes to the integer value. For example, bit 10 has an integer value of 1024 as its weighting
in the integer value is 2 to the power 10.
A single packed bit integer with a value of 1034 signifies a blown rectifier fuse, a hardware shutdown, and a
battery discharge (sum of the values for the corresponding events). The value “1034” has no meaning as such, but
when the integer is “unpacked” the individual data bits communicate the required information. This is depicted in
the following diagram.