Help with Yaskawa SGDM-04ADA-V ac servo drives

[geebow]

I have some IAI linear actuators type ISDL, that I want to make an 800x600 xy table. These actuators have 200V 400W 8 pole 3000rpm AC servo motors integrated directly onto the ball screw spindle. I would like to retain them if at all possible, but suitable IAI controllers are almost impossible to get hold of. Shaft rotary position is resolved to 17 bits by a Tamagawa absolute (1 revolution) encoder. Position data is transmitted serially at 2.5Mbaud by a two wire differential pair.

I can get a hold of some Yaskawa SGDM-04ADA-V AC servo drives at a quite reasonable price, and the voltage and power levels match. The drawback with these is that they communicate directly with the motor encoder electronics on startup for motor type data, and the drive will give a fault if the attached motor does not return a valid Yaskawa motor code.

To make it all work I figured that I could knock up an AVR or PIC interface to act as an interpreter between the Yaskawa SGDM and the IAI encoder. This would convert the serial position data to the appropriate format for the Yaskawa drive and also respond properly with the appropriate motor data when interogated at start up.

I've looked in all of the Yaskawa literature that I can find on line and cannot find any of the technical details of this electronic intercourse between the Ysakawa drives and the Yaskawa motors. So I am a bit stumped there before I start.

Secondly, I can find no data on the rotor alignment at the encoder zero point. This is critical for AC servo drives as it is the very cornerstone of proper phase synchronisation and actual rotor position.

So I have two questions for the learned gentlemen of the forum

1 - Does anybody have access to the technical details of the yaskawa SGDM-04ADA-V encoder interface and the automatic motor identification process that is performed on start-up?

2 - Am I dreaming the impossible dream? Is it just too darn difficult to mix and match AC servo drives and motors from different manufacturers? I am seriously tempted to take an axe to the existing integrated AC servo motor and replacing with an external step or brushed servo motor. These actuators are so beautiffuly made and dust tight, that I would hate to tamper with their envelope integrity. Is there a better way that I haven't thought off?

This is my first serious post. Feel free to tell me if I've posted this in the wong place, broken some ettiquite (I'm not even sure if I can spell the word), or just plain rambled on for too long.

[smurph]

I have not found any source for the Sigma II data stream format either. You could do some sleuthing and get to the bottom of the Yaskawa serial encoder signal, but you would need a Yaskawa motor to do it. And a lot of time... It's probably not worth it.

For your second point, it is a rather difficult challenge. And impossible at times. Sticking with "generic" servos instead of proprietary ones is your best bet. Advance Motion Control makes a drive to push just about any non-proprietary servo drive on the planet. "Old school" AC servos (and DC for that matter) had spec sheets that gave enough information to correctly match a drive to them. Kev for volts per 1000 RPM, rated current, peak current, etc..

But the proprietary drive/motor combos are best matched to each other. It's all driven by marketing and to simplify their support infrastructure. You can't blame them. Sell a drive and be assured to also sell a motor. And then that makes supporting it that much easier. It's also not bad for the customer either as he has a known combination that works together. It's just bad for us gear heads that are tying to make the best use of stuff that we have lying around.

Steve

[firstyear]

Hi there,

Think I may be in the same boat...
i just bought a pair of IAI linear actuators from good ol' ebay; and i'm now trying to figure out how to turn it into my dream g-code munching cnc router.

Did you have any luck finding a way to drive or control the IAI linear actuators without throwing away the inbuilt servo motors they came with?

Any help would be much appreciated.

Cheers,
Firstyear

[geebow]

Reply to firstyear

No, not much joy up to now. There seems to be a lotof technician level "hands-on" knowledge out there about particular ac servo drive/motor combinations, but little in the way of actual in depth technical understanding of the actual encoder interface details. Nobody that I have spoken to (including local Yaskawa in house technician) could even tell me how many poles their motors were. There are probably good commercial and support reasons why manufacturers nowadays seem to keep these details secret.

Some of the IAI actuators use simple A,B,Z quadrature incremental encoders, but i don't understand how they get their initial alignment for ac power sync with rotor position. Maybe they use sensorless controll untill they pick up the first Z pulse.

The IAI actuators that I have are ISD- L type which us a Tamagawa 17 bit serial encoder. It can even be programmed to hold data, which can be used for motor identification or parameter steeing when interrogated by the drive.

I suspect that the later Yaskawa servos that use serial encoders are a bit similar to this. So if your encoder does not talk nicely to the drive it will error out on you, even if the communication hardware and protocol match.

I have resigned myself to either:
A - make my own AC servo drive. I have been able to characterise the IAI servo motor. 400W, 8 Pole, Just need to figure out the orientation of the encoder zero count with the magnetic pole positions (easy eh?). Then there is the small mater of making a servo drive controller!

B - Smash the motor and encoder off the ball screw shaft and mount a stepper or servo onto it with a matching drive. Would seem to be a shame, but may turn out to be the simplest way.

Hope you have better luck than I in finding out info. In about a month or so I will be doing more testing on my IAI's to establish encoder zero position. Then it'll be plain sailling. I will post results for you then on what I find.

[firstyear]

Hi Geebow,
Thanks for your great response.

I've been searching high and low for a way to drive this contraption short of replacing the servo's.
I was lucky? to pick up an X-SEL controller as part of the deal, it's arriving tomorrow so I'll look into it then.
From what I can tell so far, the servo motor connects to both an independent driver and an independent servo cpu (which the encoder connects to) within the X-SEL controller.. the servo cpu then connects to an independent controller cpu (breakout board).

so..

1. motor > driver > controller cpu
2. motor encoder > servo cpu > controller cpu
3. controller cpu > home/office PC

PLAN A -
My new plan is to miraculously replace the controller cpu with a new cnc breakout board and cross my fingers and hope it will understand G-code.

OTHER PLAN A - Hope that geebow can make sense of the IAI info below..

http://www.intelligentactuator.com/p...ning_intro.pdf


Encoder Operation (SEL-G)

• X-SEL - 17 bit incremental encoder, 14 bit control resolution, 16384 pulses/rev

• “3-phase, Optical Incremental Encoder” allows for relative positioning (loses
position when power is cut, cable is damaged; good because home value is based
off of encoder).

• Z-phase is based on aligning motor coils with Z-pulses.

• A/B-phase sensors are used for position feedback. Controller must know where
the actuator is while moving in order to control drivers.

• After over current limit is sensed, the motor rotates until the z-pulse is sensed to
“zero” position (0.000 mm).

• Motion then occurs using the A/B pulses, feedback, and servo drivers.

• Quadrature (see diagram) allows for an effective resolution 4 times that of the encoder count (384 or 768 pulses per revolution).

A/B – phase
(384 or 768)

Z – phase
(1-4 notches)

Example encoder assembly: IS unit w/ 16 pitch ballscrew

“Quadrature”:
four distinct
states (90° out
of phase).
A B
1 0 0
2 0 1
3 1 0
4 1 1

Geebow if you have any ideas that would be great!
By the way do you think my 1st idea may work? or do you know of an alternative servo drive that can take G-CODE commands?
Cheers

[firstyear]

More info...

(X-SEL-Q)

• X-SEL Q - 15-bit rotation data backup absolute encoder
Both have a control resolution of 14 bits (16384 pulses)

*this is the one that came with my IAI linear actuators

[bobs bots]

Hi Guys.
This thread is a bit stale , but.
I also have some IA actuators (off Ebay ), but mine have the standard quadrature encoders on. (They are really neat bits of gear!)
I've got them working off a ATMEGA2560, with 24V I can get full torque but speed is limited, shortly to go to 60V drive.

Anyway I have some mitsubishi HC-KFS23 motors (200W) and a pair of MR-J2S-70B drives (700w) and you can plug them together, and you just get the "1A" error code (wrong_motor_attached_dummy).
However it is also a 2.5Mbaud 17 bit serial encoder,"OBA17-051", (the same or similar to yours).
And when the two are connected they bounce data back and forth that changes as you turn the shaft.
Any way.... if you hook up a logic analyser you can see what's going on.

When first powered up an ascii character <146> is sent and the encoder replies with <146> <1> <65> <20> <0> <0><0><0>

This appears to be some version number thingy.
Next the drive repeatdly sends <162> and gets a reply like
<162> <49> <8> <18> <15> <253> <127><192> <136>

Next you program your AVR UART to run at 2500kbaud , (quite a challenge!)
get your micro to send <162> and record the 9 byte reply while turning the shaft in a controlled fashion , squirt the numbers out another serial port with commas between them, log the serial sessin as a CSV file and read them with Excel.
Eventually you figure out enough of the protocol to use the encoders. The 9 byte response looks like:
<cmd> <type> <ph_l> <ph_m> <ph_hi> <rot_l> <rot_m> <rot_h> <crc>
Where
<cmd> is the command echoed back
<type> is the motor type (I'm guessing , I don't have any more motors to play with)
<ph_h> <ph_m> <ph_l> are the three bytes that make up the 17 bits of the phase angle (mechanical shaft angle) of the encoder, note that ph_hi has four leading zero bits , and ph_l has 2 trailing zero bits
<rot_h> <rot_m> <rot_l> Are three bytes that make up the total number of full rotations of the shaft , (I/m not sure about rot_h, as I haven't turned the shaft far enough yet!!!)
<crc> is a cyclic redundancy check, but I can't match it using any CRC checkers I have, the best guess is that it uses a standard CRC-8 polynomial of &hEA (as that's the one used in the Mitsubishi encoder patents).

Anyway my basic advice is to snoop on the data line, then replicate the command bytes , possibly <162> works for you too.

Cheers, BobT

[dm1try]

bobs bots
do you have a j2s setup software? there's a file in there called mottyp.dat. for kfs23 it gives the following id:

12FF2300 HC-KFS23

i think it should be there in your snooped data... also, if you're seriously into hacking those drives, have a look at parj2s*.dat. there's a lot of parameters to fool with. for example, No.157...181 should allow the amplifier to work with any motor, i believe. at least, i successfully reprogrammed 70b-U005 into j2s-70b and U006 to work with kfs73, kfs46 and kfs410 motors. maybe just a change in "amp capacity" param will turn off this 1A error

[bobs bots]

Hi Dm1try,
Thanks for your information.
I picked up 8 of the KFS23 with ballscrews and couplings off Ebay about a year ago. The deal included two of the MR-J2S-70B even though they were known to be incompatible.
Last week was the first time I tried to power up the drives, just to see how the encoder worked.
I intended to drive the motors with a drive of my own manufacture.

I don't have the J2S setup software , (or even any cabling to communicate with the drive) , however your information has encouraged me to consider modifying the drive in maybe a month or so.

I looked through all the responses from this motor/encoder and nothing seems to match any part of "12FF2300" . it looks like 4 hexadecimal bytes
maybe the "12" is 120volts or "23" is the motor type.

Its difficult to find much info, I would appreciate any links to information about these drives/motors.

Cheers , BobT

[mactec54]

geebow

Your drives will take step/dir so you can get them going really easy, down load the user manual number SIEPS80000015 & this one also TOE-S800-34 You get these down loads from the Yaskawa site Yaskawa America, Inc., Drives & Motion Division

This has all the information you need to get them going

[bluenone]

Dear All,

You are the first community I've ever faced, gives the detailed information about encoders and servopacks. I have too many questions about this. Please lets start the topic again.

My questions are below. I'll be appreciate if you share you comments

1. dm1try: I have a communication link wit setup161E software of Mitsubishi and you say that we can hack the software to work with any motors. Which software should we change. Is it just changing the parameters of setup161E or
reprogramme the RENESAS SH7065 or SH7034 IC via the flash programmer. It'll be very helpful. If you explain which programme should we hack and how like a begineer style.

2. dm1try: There is a SH7065F.sub and 7065.inf files in SETUP161E folder. What are they? These files are the default flash programme of servomotor I think? Actually I bought a renesas programmer (Named. E8A) with a flash development programme to reprogramme the device. Up to time I can not do this. Do you have any suggestions, any explanations about these files.

3. dm1try: Can we get the software on the MRJ2SA or MRJ2SB microprocessor or reprogramme it.

4. We have a machine that has a custom MRJ2SB-60A servomotor have a capability of using 18 bit ( not 17 bit) encoder. We bought fresh MRJ2SB from mitsubishi and change all of its parameters plus the invisible ones. Everything was OK. But we can not pass the encoder communication error. When I go in detail with SETUP161E I see that the custom one shows the encoder resolution as 18 bits (262144) and the fresh servo shows 17 bit(131072). My best quess is that the motor used in our system has 18 bit motor and mitsubishi makes a custom MRJ2SB supports 18 bit encoders.

So I think I should get the embedded code in old servo to the new servo. Is this possible do you have any suggestions about this.

5. Bobs bots: Is your serial datas are only valid for MRJ2S series or can we think that it is a general protocol used by all mitsubishi and plus yaskawa servos. Do you have any new investigations.

6. I looked for a standart RS485-RS232 converter supports 2.5 Megabaud and Embedded Ethernet, Serial to Ethernet have these devices so I think we do not have to design a fast rs485-rs232 converter.


If we start the topic again I'll be glad. I have still too many technical information and also questions about this.

best regards

[dm1try]

Originally Posted by bluenone 1. dm1try: you say that we can hack the software to work with any motors. Which software should we change. Is it just changing the parameters

yes, it's a Pr.183 called "test mode 2". not sure if it's safe to use long term, but no problem so far

2. dm1try: There is a SH7065F.sub and 7065.inf files in SETUP161E folder. What are they? These files are the default flash programme of servomotor I think? Actually I bought a renesas programmer (Named. E8A) with a flash development programme to reprogramme the device. Up to time I can not do this. Do you have any suggestions, any explanations about these files.

they are used by the shflash.exe, which comes with setup161e. it's just a sh7065f flash memory map and a bootloader

3. dm1try: Can we get the software on the MRJ2SA or MRJ2SB microprocessor or reprogramme it.

shflash.exe out of setup161e package is enough

4. We have a machine that has a custom MRJ2SB-60A servomotor have a capability of using 18 bit ( not 17 bit) encoder. We bought fresh MRJ2SB from mitsubishi and change all of its parameters plus the invisible ones. Everything was OK. But we can not pass the encoder communication error. When I go in detail with SETUP161E I see that the custom one shows the encoder resolution as 18 bits (262144) and the fresh servo shows 17 bit(131072). My best quess is that the motor used in our system has 18 bit motor and mitsubishi makes a custom MRJ2SB supports 18 bit encoders. So I think I should get the embedded code in old servo to the new servo. Is this possible do you have any suggestions about this.

what you mean with MRJ2SB-60A? MR-J2S-60B or MR-J2S-60A? you want to replace it with a fresh drive with the same letter? yes, i think it's possible. can you run a sw on a windows pc with old "custom" drive connected to its serial port? i can have a look to get an idea what's custom about it. pm me with your email please

about the custom encoder. BobT said:

When first powered up an ascii character <146> is sent and the encoder replies with <146> <1> <65> <20> <0> <0><0><0>

<65> is the encoder type for j2 super series motors. so the drive just knows that it is 17bit. it also knows 5 other types. maybe they just added another encoder id in your drive...