Accell MPC-LNK, MPC-816 Series, MPC series manual How to Deal with Noise, Parts on the Black List

How to Deal with Noise

Control involving position determination control internally deals with signals of several msec. Because this signal is at a similar level to a noise signal, no matter what control device is used, reliability and accuracy cannot be obtained without any noise countermeasures. When making a device containing a position-determination control, please keep the following in mind.

E A C 200

Electricity leakage breaker

Install noise filters to power lines to prevent external-noise: One for strong and another for weak electricity.

	AC servo is a		Motor driving		No binding with a		Separate driver lines for a servo motor and
			line (shielded)		binding band
NF							stepping motor, signal line, and DC 24V
	noise source
			Encoder line				line, and prevent relays as much as
					Separation
	AC servo		(shielded)				possible.
							Especially for robots and such, please
	driver		Electromagnetic brake
							don’t bind motor driver lines, signal lines
					Separation
							such as the one for an origin sensor, DC
					Signal line
							24V lines, etc. with the same plarail etc.
					24V line	I/O
			Pulse
					Long wiring should be
			DC24V	I/O			Install surge removers to coil resistors
	NF	PS	GND	I/O	separated by a relay etc.		such as solenoid valve, relay,
			MPC	RS-232C			electromagnetic counter, etc.
				RS-232C
	MPC power ON/OFF is by the			Pulse
	primary side of PS		RS-232C	I/O

AC200 sequencer noise is		Crosstalk between signal line and
significant
		lines 5 & 6 by relay of RS-232C for
Sequencer
		programming via cab-tire cable.
	I/O
		Please use twisted-pair cables.	RS-232C
If an MPC I/O and a sequencer I/O of another
power source are directly connected, the current comes			To be separated from strong
		Twisted-pair cable should be used for electricity systems and short
into MPC. Please separate them with a relay etc.
		pulse-signal lines, and should not be	wired. Be careful against static
	AC100
		cut in the middle or bound with
			electricity when connecting.
	Stepping	strong-electricity systems.
	motor
	driver
Relay control circuit	One-side	It is not good to bind stepping motor
	grounding
		driving lines and signal lines such as the
		one for an origin sensor, either.
MS	A surge of AC 200V becomes fatal noise. There are noise
	countermeasures for electromagnetic switch coils and contacts. Also,
	these lines and DC 24V system should never be bound together.
	ON/OFF of induction motor etc. should be preferably done by an
	SSR with zero cross rather than by a relay.
SSR

Confirm that the device is grounded.

If there is a device which stalls too frequently or produces motor position errors, there must be a clear noise source. The points are the surge based on control by coils and contacts (relay circuit) and driving lines of various large-scale motors. They become fatal noise in 200V systems and a strong noise source even in DC 24V systems.

There are plenty of coils that can become a noise source such as coils in conductors, strong AC 200V buzzers, coil noise of solenoid valves, etc. The first things to do in noise troubles are to look for coils and reevaluating power lines.

Parts on the Black List

Electromagnetically contacting parts: Noise countermeasures to coils and contacts.

AC motor: Drive by SSR. Power line wiring.

AC/DC solenoid: Noise measure to coils and contacts.

200V and 100V buzzers: Electromagnetic wave measure (distance and shielding).

Servo motor: Wiring of power line and signal lines (wire material, length, relay, and binding).

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