Allen-Bradley PowerFlex 70 Reference Manual page 68

Datalinks
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In the PLC data Table, the user enters Word 3 as a value of 100 (10.0 Secs) and
word 4 as a value of 133 (13.3 seconds). On each I/O scan, the parameters in the
PowerFlex drive are updated with the value from the data table:
Accel Time P140 = 10.0 seconds (value from output image table Word 3) Decel
Time P142 = 13.3 seconds (value from output image table Word 4).
Any time these values need to be changed, the new values are entered into the
data table, and the parameters are updated on the next PLC I/O scan.
Rules for Using Datalinks
1. 1. A Datalink consists of 4 words, 2 for Datalink x IN and 2 for Datalink x
Out. They cannot be separated or turned on individually.
2. Only one communications adapter can use each set of Datalink parameters in
a PowerFlex drive. If more than one communications adapter is connected to a
single drive, multiple adapters must not try to use the same Datalink.
3. Parameter settings in the drive determine the data passed through the
Datalink mechanism
4. When you use a Datalink to change a value, the value is not written to the
Non-Volatile Storage (EEprom memory). The value is stored in volatile
memory (RAM) and lost when the drive loses power.
32-Bit Parameters using 16-Bit Datalinks
To read (and/or write) a 32-bit parameter using 16-bit Datalinks, typically both
Datalinks (A,B,C,D) are set to the 32-bit parameter. For example, to read
Parameter 09 - [Elapsed MWh], both Datalink A1 and A2 are set to "9."
Datalink A1 will contain the least significant word (LSW) and Datalink A2 the
most significant word (MSW). In this example, the parameter 9 value of
5.8MWh is read as a "58" in Datalink A1
Datalink Most/Least Significant Word
A1 LSW
A2 MSW
Regardless of the Datalink combination, x1 will always contain the LSW and x2
will always contain the MSW.
In the following examples Parameter 242 - [Power Up Marker] contains a value of
88.4541 hours.
Datalink Most/Least Significant Word
A1 LSW
A2 -Not Used-
Datalink Most/Least Significant Word
A1 -Not Used-
A2 MSW
Rockwell Automation Publication PFLEX-RM001H-EN-P - June 2013
Parameter Data (decimal)
9 58
9 0
Parameter Data (decimal)
242 32573
0 0
Parameter Data (decimal)
0 0
242 13