Timing responsiveness – FANUC Robotics America GFK-1535A User Manual

Page 48

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VersaMax™ System Genius® Network Interface Unit User's Manual – November 2000

GFK-1535A

3

Timing Responsiveness

If an output in the station is tied to an input in the same station, the output changes
state (or value, in the case of an analog output module) within a few milliseconds of
the new output being sent from the bus controller to the NIU. (To guarantee that an
output changes state, that state must be present for at least one NIU sweep time or
one Genius bus scan time, whichever is greater.

The input which is tied to the output responds as soon as any load-effects have
settled out and input filtering is completed. This may occur as soon as the NIU’s
next I/O scan.

If the host is a PLC, an input must be present for at least one PLC sweep time plus
one Genius bus scan time plus one NIU sweep time to guarantee its detection by the
PLC. If the input changes state only briefly, and then changes again before the
input data is sent on the bus, the interim state may be overwritten in the NIU’s
internal memory by some new input state or value before it can be sent.

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