Mitsubishi Electric MELSEC iQ-R User Manual page 55

Operation
■Operation performed when a warning is output
When a digital operation value is equal to or greater than 'CH1 Process alarm upper upper limit value' (Un\G514), or the value
is equal to or smaller than 'CH1 Process alarm lower lower limit value' (Un\G520) and thus the value enters the warning
output range, a warning is output as follows.
• Alarm ON (1) is stored in 'Warning output flag (Process alarm upper limit)' (Un\G36) or 'Warning output flag (Process alarm
lower limit)' (Un\G37).
• 'Warning output signal' (X8) turns on.
• The ALM LED turns on.
In addition, an alarm code is stored in 'Latest alarm code' (Un\G2).
For details on the alarm codes, refer to the following.
Page 165 List of Alarm Codes
• The A/D conversion on a channel where a warning was output continues.
• In the simultaneous conversion mode or inter-module synchronization mode, whether to output a warning is
judged with a digital output value.
■Operation after a warning was output
After a warning was output, if the digital operation value does not satisfy the warning output condition due to being smaller
than 'CH1 Process alarm upper lower limit value' (Un\G516) or being greater than 'CH1 Process alarm lower upper limit value'
(Un\G518), Normal (0) is stored in a bit corresponding to the channel number of 'Warning output flag (Process alarm upper
limit)' (Un\G36) or 'Warning output flag (Process alarm lower limit)' (Un\G37).
In addition, when all 'Warning output flag (Process alarm upper limit)' (Un\G36) and 'Warning output flag (Process alarm lower
limit)' (Un\G37) return to Normal (0), 'Warning output signal' (X8) turns off and the ALM LED turns off. However, the alarm
code stored in 'Latest alarm code' (Un\G2) is not cleared. To clear the alarm code, turn on and off 'Error clear request' (YF)
after all the bits of 'Warning output flag (Process alarm upper limit)' (Un\G36) and 'Warning output flag (Process alarm lower
limit)' (Un\G37) return to Normal (0).
Detection cycle
When time average is specified, the function works at every interval of the time (for averaging). When count average is
specified, the function works at every count (for averaging).
When the sampling processing, moving average, primary delay filter, or digital filter is specified, this function works at every
sampling cycle.
Detection target for outputting a warning
When the digital clipping function, scaling function, shift function, or difference conversion function is used, the digital
operation value obtained after digital clipping, scale conversion, shift-and-add, or difference conversion is performed is the
detection target for outputting a warning. Set values for 'CH1 Process alarm upper upper limit value' (Un\G514), 'CH1 Process
alarm upper lower limit value' (Un\G516), 'CH1 Process alarm lower upper limit value' (Un\G518), and 'CH1 Process alarm
lower lower limit value' (Un\G520) while considering the digital clipping, scale conversion, shift-and-add, and difference
conversion.
1 FUNCTIONS
1.11 Warning Output Function
1
53