New Control on Fanuc DC Servo

[LeRa]

Hi all,

I'm trying to make a multi-purpose X-Y-translation table from an old Matsuura milling-machine. It has a Fanuc-6MB controller.

My goal is to change to a controller which I program with LabView. To do so I only need the X and Y servo motors and drives. They are the following:

servo-motors: Gettys-Fanuc DC Servo Motor Model 20 (A06B-0602-B)
servo-drives: (velocity control unit) A06B-6045-H005/H006
PCB on servo-drives: A20B-007-0360/05A

Does anyone have a schematic of the servo-drive (or PCB)?
Or a pin-out of the CN1 (Honda) connector of the PCB?

Any information that can help me is also appriciated.
I'm hoping that a simple +/-10V signal is sufficient for driving the servo's (if only I knew which pins to use of the CN1 connector). All further IO (encoder/limit-switches) can directly go to the controller.

Greetings,
LeRa

(.........who is quite new in the CNC-world)

[NC Cams]

See if you can find out if the 6 uses the same driver boards as the 5T or 5M.

I'm pretty sure have the board schematics for the 5T/M.

Ditto the pinouts for a 5T/M servo motor

[Al_The_Man]

I have the following for the 6m DC velocity unit (CN1)
You may have to decode the mnemonics but some seem obvious.
Pin
1-PRDYA
2-ENBLA
3-OVLA
4-*VRDYA
5-
6-
7-VCMD (ANALOG COMMAND?)
8-*ALM10
9-*ALM11
10-*ALM12
11-
12-
13-*COM
14-PRDYB
15-ENBLB
16-OVLB
17-*VRDYB
18-
19-
20-EC
The (*) usually means the common or complement or active low.
Al.

[LeRa]

@ NC Cams: You've got a private message (PM).

@ All_the_man: Thanks. This pinout is a big step forward for me.

[LeRa]

In relation to this, I'd also like to know the pinout of the CAV-connector of the motherboard (A20B-0008-0410/09D) of the Fanuc 6Mb controller. This is the connector from the motherboard to the servo-drives (in my case X,Y and Z).

Does anyone have this pinout?

Furthermore, does anyone know where I can download documentation about the Fanuc 6M?

Your help is appriciated.

[NC Cams]

Sorry to report that the servo drive dwgs I have are A06C-6035-004 and 6.

Don't know if they are same as the one you have.

I located 8.5"x11" pinouts of the servo interconnect but, again, these are for 5T/M and the servo amp is NOT same P/N as yours.

Sorry for the false hope.

[Al_The_Man]

Again I only have the mnemonic labels for the CAV Honda.
1-VCMBL(X)
2-VCMDM(Y)
3-VCMDN(Z)
4-ECL(X)
5-SGL
6-
7-
8-
9-
10-VRDY(X)
11-EIL(X)
12-OVLL(X)
13-E2L(X)
14-
15-
16-PRDY(X)
17-ENBLL(X)
18-CRL(X)
19-
20-ECM(Y)
21-SGM
22--
23-
24-
25-
26-VRDYM(Y)
27-E1M(Y)
28-OVLM(Y)
29-E2M(Y)
30-PRDYM(Y)
31-ENBLM(Y)
32-CRM(Y)
33-TSAL(X)
34-TSAM(Y)
35-TSAN(Z)
36-ECN(Z)
37-SGN
38-
39-
40-
41-
42-VRDYN(Z)
43-EIN(Z)
44-OVLN(Z)
45-E2N(Z)
46-
47-
48-PRDYN(Z)
49-ENBLN(Z)
50-CRN(Z)

Al.

[Dan Fritz]

I've got Fanuc 6-A and 6-B schematics, but I'm pressed for time right now. I'll try to post the relavent servo interface pages from the 6-B mother board later tonight. There are a few reed relay contacts for PRDY and ENBL signals, then there's the analog output for the velocity command (VCMD) and the tach (TSA and TSB) to each servo.

The Fanuc 20 servos used a 7volt/1000 rpm analog signal. The motor was only good for 1000-1500 rpm max, so a 10.5 volt analog velocity signal was all you need to drive them at max speed.

On power-up, the mother board of the Fanuc 6 would close the PRDY contacts, then wait for the servo to reply with a VRDY (Velocity unit ready) contact closure. Once the CNC saw the VRDY signal from the servo unit, it would turn on the ENBL (enable) signal to enable the servo's SCRs and make the analog Velocity Command signal (VCMD) active.

The TSAX and TSBX signals are the tach signals that the Fanuc mother board would create from the pulse coders. This is the only interface signal that might pose problems for you. The Fanuc 6 used a Frequency to Velocity converter (F/V) to take the pulses from the pulse coders and create a 6v per 1000 RPM tach signal for the servo. Some of these model 20 motors had tachs in them, which would solve you problem. You could just wire the tach from the motor directly to the servo at TSA and TSB. If your motors don't have tachs (just pulse coders inside), then you've got to provide a tach signal for the servo somehow. You may have to make your own F/V circuit or attach an aftermarket tach to the motor shaft.

[LeRa]

@ NC Cams: Thank you anyway (I've read your PM, I suppose I don't have to reply anymore )

@ All_The_Man: Thanks again, for the CAV pinout.

@ Dan Fritz: This is very helpfull to me, because that's what I was trying to figure out. A lot I already had, but those TSA and TSB signals were still a riddle for me. Now they are the main obstacles for connecting a custom controller.
But one thing; TSA and TSB get 7V@1000rpm or 6V@1000rpm? And are these signals linear? ( If 7V@1000rpm then 10.5V@1500rpm and 3.5V@500rpm)

Another important parameter is the number of pulses per rotation coming from the pulse-coder of the Fanuc Model 20 motor. Does anyone know this number?

I'll let you know if it all works out for me.

[Dan Fritz]

The Fanuc motors came with both 2000 line/rev and 2500 line/rev encoders. You should see a tag on the motor with a "-2000" or "-2500" on it. Some motors came with tach generators under the end cap instead of an encoder. Those motors were used on machines that had separate encoders coupled to the ballscrews. Generally, if the motor drove the ballscrew with a belt drive of some kind, the machine builders would use a separate encoder and a motor with a tach. If the motor drove the ballscrew with a direct coupling, they would generally use the motors with built-in encoders.

If the motor had a tach, then the tach signals TSA and TSB were routed to the CNC control through a separate cable (not the cable with the armature power leads). On the Fanuc mother board, those signals were then just routed back out the CAV connector to the servo amplifier. If a tach did not exist in the motor, the pulse coder signals were routed to the interpolator ICs first, then to a black square hybrid IC (A-PC06), where it was turned into a tach signal. The PC06 chip is a custom Fanuc chip, so you won't find it anywhere else. There are jumpers on the Fanuc mother board to determine if the pulse coder is 2000 or 2500 line. Another jumper selects between an "external" tach and the PC06 F/V converter output.

The tach signals for the Fanuc 20 servos was typically 6v/1000 rpm and the VCMD was 7v/1000rpm.

The encoders came in these two sizes to accomodate the different ballscrew pitches on the machines. A ballscrew with a pitch of .200 inch, .400 inch, 6mm, 8mm, etc. will use a 2000 line encoder. A ballscrew with a pitch of .250 inch, 5mm, 10mm, etc. will use a 2500 line encoder. This is so they could use a simple multiplier to make the "detect unit" an even increment, like .0001 inch or .001 mm/pulse

Attached are scans of two schematic pages. One is for the relay interface on the CAV connector, the other is for the PC06 F/V converter IC. These scans had to be "sampled down" to less than 1024 pixes horizontally to be legal for this forum, so if you can't read them I can send you higher res scans by private e-mail.

[HillBilly]

Good info Dan.

I have used this product to replace the Fanuc F/V converter on these systems.

http://www.usdigital.com/products/etach2/

This is a good source for tachometers.

http://www.servotek.com/

Darek Ashburn

[LeRa]

A small question (with hopefully a small answer):

Those analog signals (VCMD and TSA) can be positive and negative for bothe directions?