Mitsubishi Electric 800 Series Instruction Manual page 405

(T) Multi-Function Input Terminal Parameters
Analog input bias/gain calibration (Pr.902 to Pr.905, Pr.917, Pr.918)
• The "bias" and "gain" functions serve to adjust the relationship between a setting input signal and the output frequency. A
setting input signal is such as 0 to 5 VDC/0 to 10 V or 4 to 20 mADC externally input to set the output frequency.
• Set the terminal 2 input bias frequency by using Pr.902. (It is initially set to the frequency at 0 V.)
• Set the output frequency to the frequency command voltage (current) set by the Pr.73 Analog input selection by using
Pr.125 (Pr.903).
• Set the bias frequency of the terminal 1 input using Pr.917. (It is initially set to the frequency at 0 V.)
• Set the gain frequency of the terminal 1 input using Pr.918. (It is initially set to the frequency at 10 V.)
• Set the bias frequency of the terminal 4 input using Pr.904. (It is initially set to the frequency at 4 mA.)
• Set the output frequency for 20 mA of the frequency command current (4 to 20 mA) by using Pr.126 (Pr.905).
60 Hz
Bias
Pr.902
Pr.917
0
0
Frequency setting signal
0
0
Pr.902
Pr.917
• There are three methods to adjust the frequency setting voltage (current) bias/gain.
- Adjust any point with application of a voltage (current) between terminals 2 and 5 (4 and 5).
- Adjust any point without application of a voltage (current) between terminals 2 and 5 (4 and 5).
- Adjust frequency only without adjustment of voltage (current).
NOTE
• Performing terminal 2 calibration that includes a change of the setting frequency incline changes terminal 1 setting.
• Calibration with voltage input to terminal 1 sets (terminal 2 (4) analog value + terminal 1 analog value) as the analog
calibration value.
• Always calibrate the input after changing the voltage/current input signal with Pr.73, Pr.267, and the voltage/current input
selection switch.
Analog input display unit changing (Pr.241)
• The analog input display unit (%/V/mA) for analog input bias and gain calibration can be changed.
• Depending on the terminal input specification set to Pr.73, Pr.267, and voltage/current input switches, the analog value
display unit of Pr.902, Pr.903, Pr.904, and Pr.905 changes as described below.
Analog command (terminals 2, 4)
(depending on Pr.73, Pr.267, and
voltage/current input switch)
0 to 5 V input
0 to 10 V input
0 to 20 mA input
NOTE
• When the terminal 1 input specification (0 to ±5 V, 0 to ±10 V) does not agree with the main speed (terminal 2, terminal 4
input) specification (0 to 5 V, 0 to 10 V, 0 to 20 mA), and if the voltages are applied to terminal 1, the analog input is not
correctly displayed. (For example, in the initial status, when 0 V is applied to terminal 2 and 10 V is applied to terminal 1, and
the analog value is displayed as 5 V (100%).)
Use the inverter with the Pr.241 = "0 (initial value)" setting. (0% display).
404
PARAMETERS
Initial value
Gain
Pr.125 (Pr.903)
Pr.918
100%
5 V
10 V
20 mA
Pr.903
Pr.918
Pr.241 = 0 (initial value)
0 to 5 V  0 to 100% (0.1%)
0 to 10 V  0 to 100% (0.1%)
0 to 20 mA  0 to 100% (0.1%)
60 Hz
Bias
Pr.904
0 20
0 4
Frequency setting signal
0 1
0 2
Pr.904
page 406
0 to 100%  0 to 5 V (0.01 V)
0 to 100%  0 to 5 V (0.01 V) display
0 to 100%  0 to 20 mA (0.01 mA)
Initial value
Gain
Pr.126 (Pr.905)
100%
20 mA
5 V
10 V
Pr.905
page 405
page 405
Pr.241 = 1