Mitsubishi Electric R60AD8-G User Manual page 36

Operation
■Operation performed when an alert is output
Digital output values are monitored on the rate alarm alert detection cycle. When a change rate of a digital output value (from
a previous value) is equal to or more than the rate alarm upper limit value, or the rate is equal to or less than the rate alarm
lower limit value, an alert is output as follows.
• Alarm ON (1) is stored in 'Alert output flag (Rate alarm upper limit)' (Un\G38) or 'Alert output flag (Rate alarm lower limit)'
(Un\G39).
• 'Alert 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 112 List of Alarm Codes
The A/D conversion on a channel where an alert was output continues.
■Operation after an alert was output
After an alert was output, if the change rate of a digital output value does not satisfy the alert output conditions due to being
smaller than the rate alarm upper limit value or being greater than the rate alarm lower limit value, Normal (0) is stored in a bit
position corresponding to the channel number of 'Alert output flag (Rate alarm upper limit)' (Un\G38) or 'Alert output flag (Rate
alarm lower limit)' (Un\G39).
In addition, when all 'Alert output flag (Rate alarm upper limit)' (Un\G38) and 'Alert output flag (Rate alarm lower limit)'
(Un\G39) return to Normal (0), 'Alert 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 'Alert output flag (Rate alarm upper limit)' (Un\G38) and 'Alert output flag (Rate alarm lower limit)' (Un\G39) return to Normal
(0).
Detection cycle
Set the rate alarm alert detection cycle in 'CH1 Rate alarm alert detection cycle setting' (Un\G522).
The rate alarm alert detection cycle is the value calculated by multiplying the set value by the conversion cycle.
Ex.
The rate alarm alert detection cycle under the following conditions
• A/D conversion-enabled channels: CH1 to CH3
• 'CH1 Rate alarm alert detection cycle setting' (Un\G522): 5 (times)
The rate alarm alert detection cycle is 150ms. (10ms  3 (CH)  5 (times))
Digital output values are compared in 150ms intervals to check the change rate.
1 FUNCTIONS
34
1.6 Alert Output Function