STE 80722
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than was specified with the INPUT command, the controller waits until the short data
reach.
Note 1)
The controller starts reading any data sent to it only after an INPUT command is
executed. Data are set in the ring buffer, and the input data are picked up
according to the request of the INPUT statement.
Any data received before the INPUT command is executed may be ignored. Take
careful precautions when determining the data transmission timing.
Note 2)
Should program execution be suspended while the controller is waiting for data to
come in (as directed by an INPUT command), the execution of the INPUT command
will be cancelled. Should the program be resumed, program execution will start
from the step following the INPUT command. Any variables for which data was not
yet received when the program was suspended will be treated as 0.
You should keep this in mind when writing your robot language program, i.e., you
should arrange your program in such a way that it will still function properly even
should the controller (mistakenly) treat input values as 0. One way to do this is to
have the controller ask the host computer for confirmation (retransmission)
whenever the controller receives a 0. Another way to do this is to add on
check-sum data (to the data to be transmitted) and check the validity of the received
data. (For programming examples, see Para. 4.2, "Programming examples for
communication with a robot language program.")
Note 3)
In the step operation mode, which is one of the test operation modes, when the
INPUT command is executed, the program enters the wait state until data are
received. The same holds true when an INPUT command is executed directly.
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