Mitsubishi Electric FR-F740 EC Instruction Manual page 384

Selection of operation mode and operation location
External operation mode (Pr. 79 = 0 (initial value), 2)
Select the external operation mode when performing operation by providing a frequency setting
potentiometer, start switch, etc. externally and connecting them to the control circuit terminals
of the inverter.
Basically, parameter changing is disabled in external operation mode. (Some parameters can
be changed. Refer to Tab. 6-1 for the parameter list.) Refer to the detailed description of each
parameter.
When "0" or "2" is selected for Pr. 79, the inverter enters the external operation mode at power
on. (When using the network operation mode, refer to section 6.17.2.)
If you don't need to change the parameter settings frequently you can set the unit to external
mode permanently by setting Pr. 79 to "2". (If you need to change parameter settings frequently
external mode should be activated by setting Pr. 79 to "0". Then the frequency inverter will switch
to external mode automatically when the power is switched on but it can be switched to PU mode
by pressing the PU/EXT key. You can then make the parameter changes in PU mode and switch
back to external mode again afterwards by pressing PU/EXT again.)
The STF and STR signal are used as a start command, and the terminal 2, 4, multi-speed set-
ting, JOG signal, etc. are used as frequency setting.
Forward rotation
Reverse rotation
Frequency setting
6 - 234
Inverter
Power supply
start
start
potentiometer
Fig. 6-138:
External operation mode
Motor
Parameter
I001205E