Fanuc 446 Alarm

[blakester]

I'm getting a 446 alarm with a Fanuc 6M. The alarm description says the pulse coder is faulty. I have a Fanuc 4X resolver, 5M servo on the fourth axis indexer, and the additional axis card for resolver feedback. Any Ideas?

[F.Sharifi]

I'm getting a 446 alarm with a Fanuc 6M. The alarm description says the pulse coder is faulty. I have a Fanuc 4X resolver, 5M servo on the fourth axis indexer, and the additional axis card for resolver feedback. Any Ideas?

Dear Blakester

followup step by step as below:

1- go to the machine and find the Diagnostig Nr. 713 -714-715 -719 , for DGN 713 bit 0 is the Signal A for uls coder alive and bit 1 for signal B alive , bit 3 and bit7 became 1 when the puls coder is fulty , in cause of cable or internal damage ...for the 4th axis is differnet , for checking the signal A check the DGN 715 bit 0 and 1 and for checking the alarm check bit 6 from DGN 719 ...

2- then please sure the cable from puls coder and mechanical coupling of indexing table motor or ....is ok!

3- let me know the result of DGN that i explain for you ...

regards
F.Sharifi

[blakester]

I will check the diagnostics and see what they say, but I am still wondering why the alarm refers to a pulse coder when I have the resolver board with a resolver connected to it. I have set all jumpers and parameters that tells the control that the 4th uses a resolver for feedback. I have checked the cables with a meter from one end to the other also.

[F.Sharifi]

I will check the diagnostics and see what they say, but I am still wondering why the alarm refers to a pulse coder when I have the resolver board with a resolver connected to it. I have set all jumpers and parameters that tells the control that the 4th uses a resolver for feedback. I have checked the cables with a meter from one end to the other also.

Dear Blakester
For Fanuc system puls coder or resolver induction is the same ! ...the DGN just check the activity of Signal A&B , is not important that signal made by resolver or induction , then i need to know the DGN that i explain for you ,...if you wanna know what do you do ,...let me know the DGN 713-714-715-719..

regards
F.Sharifi

[blakester]

Here are the diagnostics:

713 = 00000000
714 = 11110000
715 = 1000111(bit 0 flickers between 0 & 1)
719 = 11010111

[F.Sharifi]

Here are the diagnostics:

713 = 00000000
714 = 11110000
715 = 1000111(bit 0 flickers between 0 & 1)
719 = 11010111

Dear Blakester
713 is ok- 714 is ok- 715 bit 0 & 1 & 2 mustbe 0 - 719 bit 6 must be 0 -...ok then if resolver for indexing table is kind of rotary resolver induction , ussualy its happen when you have loos the gap between scale and scanner ,..the normal gap is about .2 or .3 mm ( you can use normal paper for adjusting) ,..or disconected wirring from scale or scanner , it means 2 wire on scale must be making short circuite and 4 wire from scanner made signal A & B ,...please check it all ,...at last if you have Maitenece doc. B54045E/02 go to 254 section 6.1.6 for detail ,...but i thinks its better firstly you have to sure the area between scale and scanneris ok and clean !

keep in touch my brother
F.sharifi

[10001001]

This information is for F.Sharifi.

I am a friend of Blakester I spent a good deal of time in his shop today helping him trouble shoot this problem, here are some things that are puzzling me and may be helpful to you.

1. The 4th axis has a rotational inductive resolver not linear scales and scanner.

2. We have verified all of the wiring to the 4th axis resolver card and all checks out. I am not exactly clear on how Fanuc is using this resolver, but it looks as if the resolver card should be supplying a sine wave to one of the coils on the resolver and a cosine wave to another coil on the resolver, and then reading back a sine wave from the third coil on the resolver. This wave form output from the resolver should represent the rotational position of the motor shaft.

Please correct me if I am wrong

If this is correct the strange thing that I can not figure out is. The Axis card is only outputting a wave form on one set of windings. The other output appears dead.

Blakester and I have tested three cards and all three are doing the same thing, based on that we can probably rule out that the 4th axis card is bad.

If anyone has more information it will be greatly appreciated

[Al_The_Man]

but it looks as if the resolver card should be supplying a sine wave to one of the coils on the resolver and a cosine wave to another coil on the resolver, and then reading back a sine wave from the third coil on the resolver. This wave form output from the resolver should represent the rotational position of the motor shaft.

Normally the way a resolver works, and I have never 'scoped' a Fanuc version, is that the card supplies the primary (rotor) winding with a constant amplitude sine wave, typically 10khz, 4 to 10vp/p, the other two windings, sine & cosine feed back a signal to the card, these signals are a low frequency modulation of the 10khz, the modulation is dependant on the rpm of the motor.
So you may have to turn the motor to see any output on the sin/cos outputs.
Al.

[10001001]

Yes, I agree and have seen resolvers configured as you described. However the FANUC manuals show to wire the resolver as I described in the earlier message. The FANUC Manual also states in its text that a sine and cosine wave are applied to two of the coils and a 10v sine wave should be output on the reference coil.

[Al_The_Man]

The wiring diagrams I have that show the resolver for position feedback (DC motors) show two feedback windings sine/cosine used for position and direction, if you have only one feedback, it is not possible to obtain direction?
Al.

[blakester]

Al,

Any chance we could get a copy of the connection you are looking at between the resolver board and the resolver itself?

[Al_The_Man]

These are in the Fanuc 10 manual, but the motors are the same, I believe.
I could send a copy of this if you think it will help.
Al.