Rockwell Automation 1771-QC , D17716.5.25 SER/B SERVO POS User Manual

Page 141

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Formatting and Interpreting Data Blocks

Chapter 7

7Ć59

You must include a next moveset pointer word if you turn off the end of
program bit in the moveset control word.

When the 1771-M3 controller has transferred the last move of a moveset
to the 1771-ES expander, the 1771-M3 controller immediately requests
transfer of the next moveset, using the next moveset pointer.

Because the time required for status block transfer and moveset block
transfer, you must be sure that the last two moves of any moveset that is to
be followed immediately by another moveset have sufficient execution
time to allow the necessary block transfers. If you allow insufficient time,
a momentary decrease in axis velocity, or an unintended dwell, may occur
between continuous moves in two consecutive movesets. If the delay is
greater than 30ms, the next move will not execute until you issue a motion
command. The insufficient-data bit will be on in this condition.

Important: The moveset block specified by the next moveset pointer
must have an allowable block ID.

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