Galil DMC-1800, DMC-1700 user manual Communication, Stability

Unable to read main or	The encoder does not work	1.	Wrong encoder
auxiliary encoder input.	when swapped with	connections.
	another encoder input.
		2.	Encoder is damaged
		3.	Encoder
		configuration incorrect.
Unable to read main or	The encoder works	1.	Wrong encoder
auxiliary encoder input.	correctly when swapped	connections.
	with another encoder input.
		2.	Encoder
		configuration incorrect.
		3.	Encoder input or
		controller is damaged
Encoder Position Drifts	Swapping cables fixes the	1.	Poor Connections /
	problem	intermittent cable
Encoder Position Drifts	Significant noise can be	1.	Noise
	seen on CHA and / or CHB
	encoder signals

Check encoder wiring. For single ended encoders (CHA and CHB only) do not make any connections to the CHA- and CHB- inputs.

Replace encoder

Check CE command

Check encoder wiring. For single ended encoders (CHA and CHB only) do not make any connections to the CHA- and CHB- inputs.

Check CE command

Contact Galil

Review all terminal connections and connector contacts.

Shield encoder cables

Avoid placing power cables near encoder cables

Avoid Ground Loops Use differential encoders Use +/-12V encoders

Communication

	SYMPTOM	DIAGNOSIS		CAUSE	REMEDY
	Cannot communicate with	Galil software returns error	1.	Address conflict	Change address jumper positions,
	controller.	message when			and change if necessary (Chap 4)
		communication is	2.	IRQ address
		attempted.			Select different IRQ
			3.	Address selection	From Galil software, edit Galil
				does not agree with
				registry	Registry
				information.
Stability

SYMPTOM	DIAGNOSIS		CAUSE
Servo motor runs away	Reversed Motor Type	1.	Wrong feedback
when the loop is closed.	corrects situation (MT -1)		polarity.
Motor oscillates.		2.	Too high gain or
			too little damping.

REMEDY

Reverse Motor or Encoder Wiring (remember to set Motor Type back to default value: MT 1)

Decrease KI and KP. Increase KD.

182 • Chapter 9 Troubleshooting DMC-1700/1800