Mitsubishi Electric 800 Series Instruction Manual page 413

(T) Multi-Function Input Terminal Parameters
Analog current input loss condition (Pr.778)
Set frequency
60Hz
Current input
decrease detection
∗1
2mA 4mA

When the Pr.573 ≠ "9999" and terminal 4 (terminal 2) is
calibrated to 2 mA or less with Pr.902 (Pr.904), analog input
frequency that is 2 mA or less will become input current loss, thus
it will not be as the bias setting frequency.
NOTE
• Changing the terminal assignment using Pr.190 to Pr.196 (Output terminal function selection) may affect the other
functions. Set parameters after confirming the function of each terminal.
Continuous operation at analog current input loss (Pr.573 = "1, 4",
Pr.777)
• When Pr.573 = "1", operation is continued with the output frequency before the current input loss.
• When Pr.573 = "4" and Pr.777 ≠ "9999", operation is continued with frequency set in Pr.777.
• When the start command is turned OFF during the input current loss, deceleration stop is immediately performed, and the
operation is not restored even if start command is input again.
• When the current input is restored, the LF signal is turned OFF, and operation is performed according to the current input.
• The following is the operation example during External operation.
Output frequency
Analog input
20 mA
4 mA
STF
LF signal
• PID control (reverse action)
Output frequency
20mA
Set point (fixed)
Measured value
4mA
STF
LF signal
PID signal
NOTE
• When the setting is changed to continuously operate after the input current loss (Pr.573 = "1, 4"), the motor will operate as
the frequency before loss is 0 Hz.
412
PARAMETERS
When Pr.902 (Pr.904) = 0%
20mA
Analog input
Normal use range
• When the condition of current input to the terminal 4
(terminal 2) continues to be 2 mA or less for Pr.778 setting
time, it is considered as loss of analog current input and
alarm (LF) signal is turned ON. The LF signal will turn OFF
when the current input becomes 3 mA or higher.
• For the LF signal, set "98 (positive logic) or 198 (negative
logic)" in any of Pr.190 to Pr.196 (Output terminal
function selection) to assigns the function.
Pr.573=1 : Operation continued with the frequency before being lost
Pr.573=4 : Operation continued with Pr.777 setting
Return
Input current
decrease
3 mA
2 mA
Pr.573=1 : Operation continued with the frequency before being lost
Pr.573=4 : Operation continued with Pr.777 setting
Input current
decrease
Return
3 mA
2 mA
On during input decrease
Time
Time