Mitsubishi Electric NZ2GF2B-60TCTT4 User Manual page 142

(c) How to set process alarm
1.
Set "Method selection" to "Param write(Temperature input mode)".
"CC IE Field Configuration" windowSelect the temperature control module from "List of
stations"[CC IE Field Configuration][Online][Parameter Processing of Slave Station]
2.
Set "0: Enable" to "CH Process alarm warning output enable_disable setting".
3.
Set "CH Process alarm lower lower limit value", "CH Process alarm lower upper limit value",
"CH Process alarm upper lower limit value", and "CH Process alarm upper upper limit value".
(d) Precautions
When resolution is "1", the temperature process value (PV) of the temperature control module is rounded off
from the actual temperature. For the process alarm also, the temperature process value (PV) rounded off from
the actual temperature determines the alert occurrence.
(2) Rate alarm
The temperature process value (PV) is monitored every rate alarm alert detection cycle. An alert occurs when the
change from the previous monitoring is greater than the rate alarm upper limit value, or smaller than the rate
alarm lower limit value. The rate alarm is helpful to monitor the change of the temperature process value (PV) in
a limited range.
PV Present value - PV Previous value  Rate alarm upper limit value
PV Present value - PV Previous value  Rate alarm lower limit value
The alert is cleared when the temperature process value reaches within the range of the formulas above. An alert
is not cleared even by resetting the error.
(a) Checking the alert occurrence
While the rate alarm is occurring, CH Alert occurrence flag (RX18 to RX1B) turns on, and the ALM LED turns
* 1
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))
*1 The ALM LED prioritizes the detection of other errors for which the ALM LED flashes (such as the detection of loop
disconnection).
(b) Checking the alert clearance
CH Rate alarm upper limit (b4 of RWr4 to RWr7) or CH Rate alarm lower limit (b5 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 rate
alarm is occurring.
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