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I/O Area Section 9-3
Input Response Time
Settings
The input response times for each Input Unit can be set in the PLC Setup.
Increasing the input response time will reduce chattering and the effects of
noise and decreasing the input response time allows higher speed input
pulses to be received.
The default value for input response times is 8 ms and the setting range is
0.5 ms to 32 ms.
Note If the time is set to 0 ms, there will still be an ON delay time of 20
µs max. and
an OFF delay time of 300
µs due to delays caused by internal elements.
Output Bits
A bit in the I/O Area is called an output bit when it is allocated to an Output
Unit. The ON/OFF status of an output bits are output to devices such as actu-
ators. There are three ways for the status of output bits to be refreshed to an
Output Unit: normal I/O refreshing, immediate refreshing, and IORF(097)
refreshing.
Normal I/O Refreshing The status of output bits are output to external devices once each cycle after
program execution.
In the following example, CIO 000201 is allocated to an actuator, an external
device connected to an output terminal of an Output Unit. The ON/OFF status
of CIO 000201 is output to that actuator once each cycle.
Immediate Refreshing When the immediate refreshing variation of an instruction is specified by
inputting an exclamation point just before the instruction, and the instruction’s
operand is an output bit or word, the content of the word containing the bit or
the word itself will be output just after the instruction is executed. This immedi-
ate refreshing is performed in addition to the normal I/O refreshing performed
once each cycle.
Input from switch
Input bit
Pulses shorter than the time
constant are not received.
Input time constant
Input time constant
000201 OUT 000201
CIO 000201
Ladder symbol Mnemonic
CPU Unit
Bit allocation
Output Unit
Actuator
Once
each
cycle
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