Setting Input Gain Maximum Frequency (Terminals 2, 4) (Pr. 125, Pr. 126) - Mitsubishi Electric FR-A800 Series Beginner's Manual

Parameter
Pr. 79 = „0" (external operation mode, switchable to PU, initial value)
Pr. 79 = „2" (external operation, non-switchable)
When parameter 79 is set to „0" or „2", external operation mode is activated when the power supply
is switched on. It is not generally possible to adjust parameters while the unit is in this mode.
If you do not often need to adjust parameters you can prevent switching to PU operation mode by set-
ting parameter 79 to „2".
However, if you often need to change parameter settings you should set parameter 79 to "0" so that
you can switch back to PU operation mode by pressing PU/EXT on the parameter unit. Parameters can
be entered and edited in PU mode. When you have finished making your settings you can then press
PU/EXT again to switch back to external operation mode.
When the inverter is in external operation mode start commands are executed with signals applied to
terminals STF (forward) and STR (reverse). The frequency/speed can be set with an analog signal (cur-
rent or voltage) or by selecting preset speed settings on terminals RH, RM and RL.
Pr. 79 = „1" (PU operation mode)
When parameter 79 is set to „1" the inverter switches to PU operation mode when it is powered up and
it can be operated with the keys on the parameter unit.
When operation mode 1 is set it is not possible to switch the operation mode by pressing the PU/EXT
key.
Pr. 79 = „3" (PU/External combined operation mode 1)
Select this combined mode when you want to set the speed frequency with the setting dial of the pa-
rameter unit and use the external terminals for the motor start signals.
You cannot switch the operation mode with the PU/EXT key in this mode.
You can also use external signals to set the speed. If an external speed setting signal is used it has high-
er priority than the frequency setting on the parameter unit.
Pr. 79 = „4" (PU/External combined operation mode 2)
Select this combined mode when you want to activate the start signals with the parameter unit and
set the speed frequency with an external potentiometer or the speed setting parameters.
Here too, you cannot switch modes with the PU/EXT key.
6.2.8

Setting input gain maximum frequency (terminals 2, 4) (Pr. 125, Pr. 126)

The "gain" function serves to adjust the relationship between a setting input signal and the output fre-
quency. A setting input signal is such as 0 to 5 V DC/0 to 10 V or 4 to 20 mA DC externally input to set
the output frequency.
Set Pr. 125 „Terminal 2 frequency setting gain frequency" to change the frequency for the maximum
analog voltage input (at 5V, initial value). Set Pr. 126 „Terminal 4 frequency setting gain frequency" re-
spectively to change the frequency for the maximum analog current input (at 20 mA, initial value).
For more details refer to the Instruction Manual of your inverter.
Frequency Inverters - Beginner's Guide
The simple mode parameters in detail
6 - 7