4-2 Function Mode Normally, the Inverter performs proportional integral compensation (PI control) for speed control so that the difference between frequency reference and actual rpm becomes zero. If one load is operated by several motors, however, proportional control (P control) may be required. To enable proportional control (P control), allocate the P/PI switching function to any of multi- function input terminals S1 to S8 (set "43" in any of C001 to C008) via the Digital Operator, and turn on the terminal. If you choose to enable proportional control, set a "KPP" value in H052 (P control proportional gain).
Torque P control PI control 100% (A) The relationship between the KPP value and speed change ratio is expressed broadly in the following formula: 4 0 rpm (Speed change ratio) = 10 (KPP set value) % Functions The relationship between speed change ratio and speed error is expressed broadly in the following formula: (Speed change ratio) = Speed error at rated torque (A) Synchronous rpm at base frequency Ч 100% Forced Terminal Block Function (F-TM) •This function forcibly enables operation via the control terminal block by turning on/off the multi- function terminal if the frequency reference/RUN command sources are not set to the control terminal block.
•If the Forced Terminal Block function is selected in the multi-function input selection, the Inverter is operated with the signal from the frequency reference source and RUN command source selected in A001 and A002, when the input signal is OFF. When the signal is ON, the Inverter is forced to operate with the frequency reference or RUN command from the control circuit terminal block. •If you switch on/off this function during operation, the RUN command is reset to stop the Inverter output. Before resuming operation, turn off the RUN command from each command source to avoid possible danger and then input it again.
Analog Command Hold Function •While the AHD terminal is turned on, the Inverter keeps external analog input results on hold. 4-89 Data Symbol Function name Description 51 F-TM Multi-function input selection Forced terminal Available input terminals C001 to C008 Related codes A001, A002 Parameter No. Function name Data Default setting Unit C001 to C008 Multi-function inputs 1 to 8 selection 65: AHD (analog command held)