Rockwell Automation 1771-OFE/B Analog Output Module User Manual - Manual (Page 49)

4-13
Publication 1771Ć6.5.30 - November 1998
Module Update Time
Update time is defined as the amount of time it takes for the output
module to receive a block transfer scan and update all output
channels. Refer to Figure 4.9. The output module updates the four
output channels in:
•
8 milliseconds when BCD data format and scaling are used
•
1.6 milliseconds when binary data format and no scaling are used
Block transfer from the processor is inhibited during this time span.
Figure 4.9
Module Output Update Time
X
Y Y Y
X
12896
Legend:
X = BlockTransfer inhibited while
update is being completed for 8
milliseconds with BCD and scaling,
1.6 milliseconds with binary and no
scaling
Y = Blocktransfer enabled
If you plan to add more block transfer modules to your system at
some future date, we recommend that you reserve a few words in the
first available time/counter value area of the data table for block
transfer addresses. This eliminates the need to reconfigure your data
table.
In this chapter you learned how to write data to the module, the data
formats used for block transfer, special programming techniques, and
were given sample program examples.
System Expansion
Recommendations Ć PLCĆ2
Processors Only
Chapter Summary