Mitsubishi Electric MELSEC iQ-R Series Programming Manual page 202

■Inverse engineering value conversion
This function block converts the setting value (SV) of an engineering value into a setting value (SV) in percentage (%).
100
SV(%)= ×(SV-RL)
RH-RL
RH: Engineering value high limit, RL: Engineering value low limit, SV: Setting value
■Disable alarm detection
This function block sets whether to detect alarms (ALM) or not in the deviation check.
Item
Disable alarm detection by setting tag data
Disable alarm detection by loop stop processing
■Auto tuning (AT1)
This function block detects dynamic characteristics and automatically calculates a proportional gain (Kp), integral time (Ti),
and derivative time (Td) for PID operations. ( Page 594 Auto tuning)
• Auto tuning is for setting initial values of the proportional gain (Kp), integral time (Ti), and derivative time (TD) for PID
operations. The ZN method: Ziegler-Nichols' step response method is used for calculating the values.
• Auto tuning can be performed only in the MANUAL mode.
■Loop stop processing
When the stop alarm (SPA) of the alarm (ALM) is TRUE, this function block performs the following processing.
• MV is cleared to 0.
• The control mode is automatically switched to MANUAL.
• When DVLA of the alarm (ALM) has occurred, the DVLA is reset.
• No alarm is detected in the deviation check.
■Processing operation
: Performed, : Not performed
Control mode Processing operation
Deviation check

MAN, CMV, AUT

CAS, CSV
*1 An alarm whose corresponding bit is TRUE (Valid) in the disable alarm detection (INH) is not detected.
*2 Auto tuning can be performed only in the MANUAL mode.
10 LOOP CONTROL OPERATION
200
10.4 Velocity Type PID Control (Disable Tracking for primary loop) (M+P_PID)
PID operation Engineering
value
conversion
 
 
Disable alarm detection processing
If the following bits in the disable alarm detection (INH) are TRUE, no DVLA of
the alarm (ALM) will be detected.
• ERRI
• DVLI
Page 200 Loop stop processing
Inverse
engineering
value
conversion


Alarm Auto tuning
*1 *2
 
*1
 