Hitachi SJ700-2 instruction manual Home search function

Chapter 4 Explanation of Functions

4.3.11 Home search function

The home search function allows you to make the inverter locate the motor shaft at a specified position. You can use this function, for example, to stop a metal-cutting machine to replace the tool attached to the main spindle. When using the home search function, be sure to insert a reference point pulse signal between the EZP pulse and EZN pulse signals from the encoder.

Related code

P011: Encoder pulse-per-revolution (PPR) setting

P014: Home search stop position setting

P015: Home search speed setting

P016: Home search direction setting

P017: Home search completion range setting

P018: Home search completion delay time setting

P023: Position loop gain setting

C001 to C008: Terminal [1] to [8] functions

C021 to C025: Terminal [11] to [15] functions

C026: Alarm relay terminal function

Item	Function code	Data or range of data		Description
Encoder pulse-per-revolution	P011	128. to 9999. or 1000 to 6553
(PPR) setting		(10000 to 65535) (pulses)
Home search stop position	P014	0. to 4095.
setting
Home search speed setting	P015	0.00 to 99.99 or 100.0 to 120.0	See Note 1.
		(Hz)
Home search direction setting	P016	00
		01
Home search completion range	P017	0. to 9999. or 1000 (10000)
setting		(pulses)
Home search completion delay	P018	0.00 to 9.99 (s)
time setting
Position loop gain setting	P023	0.00 to 99.99 or 100.0 (rad/s)
Terminal function	C001 to C008	45
Terminal function	C021 to C025	23	ORT: Orientation
Alarm relay terminal function	C026		POK: Positioning end signal
Operation command (FW or		ON
ORT terminal
		ON

Output Frequency

(2)

(1) Home search speed setting (P015)

(3)

				Home search completion
				range setting (P017)
Z pulse
POK signal
		ON			(4)
			Home search completion delay
	Speed control Position control
			time setting (P018)

1)When the operation command is turned on with the ORT terminal turned on, the inverter accelerates the motor to the speed specified by the home search speed setting (P015), and then runs the motor at a constant speed. (If the motor is already running, the inverter changes the speed to the home search speed when the ORT terminal is turned on.)

2)After the home search speed is reached, the inverter switches to position control mode when it detects the first Z pulse.

3)The inverter performs position control by rotating the motor by one turn as the target amount from the position specified by the home search stop position setting (P014) when running the motor forward, or by two turns as the target amount from the home search stop position (P014) when running the motor reversely. In this case, the shorter the deceleration time, the larger the position loop gain setting (P023) becomes. (This deceleration time does not follow the deceleration time setting.)

4)The inverter outputs a POK signal when the time specified by the home search completion delay time setting (P018) elapses after the remaining number of pulses enters the range specified by the home search completion range setting (P017). (The inverter continues to output the POK signal until the ORT

terminal is turned off.) After home search operation has been completed, servo lock status continues until the operation command is turned off.

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