Mitsubishi Electric NZ2GF2B-60TCTT4 User Manual page 166

(g) Other conditions
In addition to the conditions described up until here, if any of the following conditions applies, auto tuning ends
in failure.
• Hardware failure has occurred.
• In standard control, CH Proportional band (P) setting (address: 102H, 132H, 162H, 192H) is changed to
0. (has been set to two-position control) (Page 318, Appendix 3 (7))
• In heating-cooling control, CH Heating proportional band (Ph) setting (address: 102H, 132H, 162H,
192H) is changed to 0. (has been set to two-position control or three-position control) (Page 318,
Appendix 3 (7))
(8) Operation on completion of auto tuning
(a) Normal completion
The temperature control module operates as follows.
• Turns off CH Auto tuning status (RX20 to RX23)
• Stores the PID constants in the remote buffer memory (Page 160, Section 8.3.7 (3))
• Stores a value in CH Loop disconnection detection judgment time (address: 116H, 146H, 176H, 1A6H)
(If this was set to 0 (s) at the start of auto tuning, the setting remains unchanged.)
(b) Abnormal completion
The temperature control module operates as follows.
• Turns off CH Auto tuning status (RX20 to RX23)
• Does not store the PID constants in the remote buffer memory. (Page 160, Section 8.3.7 (3))
(9) Checking the completion of auto tuning
The completion of auto tuning can be checked by the status change from on to off in CH Auto tuning status
(RX20 to RX23).
(10)Adjustment after auto tuning
To change the control response toward the PID constants calculated by auto tuning, change the setting in the
following remote buffer memory area.
• CH Control response parameter (address: 10FH, 13FH, 16FH, 19FH) ( Page 329, Appendix 3 (18))
In the system where the temperature rise rapidly, auto tuning may not be performed properly due to the excessive
temperature rise during the auto tuning. Therefore, for a sequence program to perform auto tuning, incorporate the alert
function so that the auto tuning will be stopped if an alert occurs.
For details on the sequence program, refer to the following.
Page 232, CHAPTER 9
(11)During auto tuning loop disconnection detection function
For details on the during AT loop disconnection detection function, refer to the following.
Page 214, Section 8.3.20
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