Alert Output Function - Mitsubishi Electric NZ2GF2B-60TCTT4 User Manual

8.2.1

Alert output function

An alert can be output when the temperature process value (PV) meets the condition set in advance using this
function. Use this function to activate danger signals of devices or safety devices.
There are two types of alert: process alarm and rate alarm.
(1) Process alarm
An alert occurs when the temperature process value (PV) reaches the process alarm upper upper limit value or
more, or the process alarm lower lower limit value or less.
The alert is cleared when the process value reaches a value less than the process alarm upper lower limit value,
or a value more than the process alarm lower upper limit value. An alert is not cleared even by resetting the error.
(a) Checking the alert occurrence
When an alert occurs, CH Alert occurrence flag (RX18 to RX1B) turns on, and the ALM LED turns on.
In CH Alert definition (RWr4 to RWr7), whether it is an upper limit alert or lower limit alert can be checked.
(Page 303, Appendix 2 (5))
(b) Checking the alert clearance
When the alert is cleared, CH Process alarm upper limit (b2 of RWr4 to RWr7) or CH Process alarm lower
limit (b3 of RWr4 to RWr7) becomes 0 (OFF). Also, CH Alert occurrence flag (RX18 to RX1B) turns off and
the ALM LED turns off.
In CH Alert occurrence flag (RX18 to RX1B) and on the ALM LED, the alert is not cleared when an alert other than the
process alarm is occurring.
Temperature
CH□ Process alarm upper limit
(b2 of RWr4 to RWr7)
CH□ Process alarm lower limit
(b3 of RWr4 to RWr7)
CH□ Alert occurrence flag
(RX18 to RX1B)
An alert
occurs.
Upper upper
limit value
Upper lower
limit value
Temperature
process
value (PV)
Lower upper
limit value
Lower lower
limit value
ON
OFF
OFF
ON
OFF
Alert output range
Out of alert output range
Included
An alert is cleared.
An alert is
cleared.
An alert
occurs.
ON
ON
Controlled by the temperature
control module
CHAPTER 8 FUNCTIONS
Temperature
Input
Time
139
8