Old Plasma table retrofit - Sanyo Denki PY2 amps

[derekmccoy]

Hi, I've been tasked with retrofitting an old plasma table. I should disclose that although I'm quite technical, all I know about CNC and servo drives, I have learnt this past week. After doing a bit of research, it seems 90% of this sort of stuff is either Mach3, UCCNC, or LinuxCNC. Then I stumbled across the Masso controller on Youtube and I have to say looks very appealing.

Ok so the table is a SAF Plasmatome 20 with Sanyo Denki servos. PY2 amps (PY2A015 version) and P5 motors. There's three of these units and seems to be arranged in an XXY setup (Labelled "LE", "LM", and "T"). These amps are connected via a CN1 connector to an antique looking circuit board with what looks like relays and a transformer. From there, two leads go to the controller's "X Encoder Input" and "Y Encoder Input" plugs. Now, I thought servos were a closed loop system so this is a bit confusing.

The CN1 connector is detailed in the PY2 installation manual and shows pins for "Forward revolution pulse" and "Backward revolution pulse". This suggests it's CW/CCW am I right? Although it also says "Position command pulse input" and "Velocity command input" so is it possible it's also Pulse/Direction? Who knows, I'm a bit lost to be honest, haha.

Full manual here: https://s3.amazonaws.com/Icarus/DOCUMENTS/SanyoDenki_Manuals_2000.pdf
Page 4-5 shows the CN1 wiring

Can Masso talk to these servos? I'm not even sure if they are digital or analog. Any help is appreciated. Many thanks.

 

[breezy]

@derekmccoy

Derek,

Quick read of PDF seems that the drives can be set into S & D mode and the pins in CN1 are

• 28 & 29 Step
  
• 26 & 27 Direction
  

Section 9.1.8 Position Control Type Specifications the second section in Fig. 9-13 Command Pulse Type shows the pin numbers and Fig. 9-14 Command Pulse Timing shows that a "low" on pins 26 & 27 is "backward" with a "high" as forward rotation.

You may need to connect other pins to "enable" the drive, which you should be able to work out from the information in the PDF.

Regards,

Arie.

 

[derekmccoy]

Indeed it does, and it says go to page 7-43 for details. Looks like I need to change Bit 6 from 0 to 1.
Although I need that handheld control unit mentioned on page 7-2, the Remote Operator RP-001 which, looking on eBay, seems to be a very expensive piece of kit for what it is.

Now, any indication on whether these drives are digital or analog. If analog, can Masso talk to them?

 

[breezy]

Derek,

Now, any indication on whether these drives are digital or analog. If analog, can Masso talk to them?

As I already stated in Section 9 Specs Fig. 9-13 Command Pulse Type is showing pulse shape and Fig. 9-14 Command Pulse Timing show the timing of the pulse so therefore the drivers take a digital input.

Regards,

Arie.

 

[derekmccoy]

Apologies, I'm not clued up with this so I could not see from that figure how to deduce that it is digital or analog.

I've done a bit more reading and the simple fact that it does take "pulse command" makes it inherently digital, is that right? If it were analog, it would be a +/-10V signal?

The manual does state that it can take "Pulse train input" (digital?), "analog input" or "serial input". So for digital use the pulse command pins (26-28 on CN1), analog use the velocity command pins (20-21), is it that simple?

So it's looking ever more promising that Masso can work with these drives.

 

[evermech]

@derekmccoy

No question about it Masso will work with these servo drives. I built a system with similar servo drives about a year ago with no problems so you should be able to too. Once you get your axis in motion you will find a lot of help on the forum with regards to plasma operation from several users. FYI I don't think I've ever seen @breezy give a wrong answer or bad advise yet, very knowledgable about Masso products.

Guy

 

[breezy]

Thanks, Guy.

I don't think I've ever seen @breezy give a wrong answer or bad advise yet, very knowledgable about Masso products.

I gave one or two wrong answers early on, mainly because I didn't have my facts right. In regards to the MASSO I've a reasonable knowledge about the mill version but less with the plasma and lathe versions. I think Peter is extremely knowledgeable in regards to the MASSO product. I've only been using the MASSO at most once a week from about a year ago and none since going into "lockdown" in February.

Derek,

The manual does state that it can take "Pulse train input" (digital?), "analog input" or "serial input". So for digital use the pulse command pins (26-28 on CN1), analog use the velocity command pins (20-21), is it that simple?

Yes it is that simple.

Regards,

Arie.

 

[derekmccoy]

Thanks for the info. I've gone over the manual and it mentions this about input voltage on page 9-3:

2.0 VDC (at 1000 min?1 command, forward motor revolution with positive command, maximum input voltage 10 V).

No mention of amperage. What is Masso's output voltage?

 

[derekmccoy]

@breezy Sorry to bother you again but it seem you know your stuff.

I've been reading the manual again and it mentions the pulse command form under "position command pulse train form". Does it mean a position command when in position control mode? As opposed to torque mode and velocity mode? Do I need to make sure my servos are set to "position control mode" as mentioned in page 7-58?

 

[breezy]

Derek,

Do I need to make sure my servos are set to "position control mode" as mentioned in page 7-58?

YES.

MASSO is a position mode controller, it calculates how many pulses are needed to move the required distance, based on the calibration information in each axis. For the other modes available feedback signals are required which MASSO doesn't provide for.

Regards,

Arie.

 

[derekmccoy]

I'm not as clueless as I thought then, as I now feel more confident about this I have ordered a 4 axis Plasma Masso G3 from 3DTEK.

I think I will use this thread as a build log in the hope others will find it useful if they have these Sanyo Denki drives.

Reading further, it seems I need to make other parameter changes. Unfortunately, to do this I need the Sanyo Denki RP-001 Remote Operator handheld module which is an extortionate amount of money for what it is ( 400 from eBay).

To make certain main changes, or what Sanyo calls "modification of a system parameter", first the drive needs to be set to allow these changes. This setting is called "system parameter rewrite" and its located on Mode 2, Page 7, func6, bit 7. This bit needs to be set to 1. Also the change doesn't happen until the drive is powered off. So in short - change func6 bit7 to 1, make the system parameter change then power off and power back on. I have highlighted system parameters with ?? .

The changes I think I have to make are:

Change to Position mode ??
Mode 4, Page 3 - TYPE (Control Type)
Currently set to 'Velocity', changed to 'Position'

Change to step/dir
Mode 2, Page 0 - PMOD (Position command pulse train form)
Changed bit6 to 1 (Code + pulse train)

Change CN1 pin39 to 'Positioing complete'
Mode 2, Page 5 - func4 (Amplifier function select 4)
Currently set to 00000001, changed to 00000100 (CN1-39 pin output select to INP: Positioning complete)
I've only changed this because the manual says "The standard value is set at 00000100 in the position control mode" so I thought best to set it to the default value when in Position mode.

Use the motor encoder & invert over-travel logic
Mode 2, page 1 - func0 (Amplifier function select 0)
bit7 (position loop encoder) currently set to 1 (fully closed encoder), changed to 0 (motor encoder)
This is another guessed change. The existing 25 year old controller had encoder inputs. I read somewhere that older systems closed the loop at the controller. I'm guessing this is so that the controller can know the position of the motors.
UPDATE: Also change bit 5 to 1 (over-travel logic, this saves on having to power pins 33 and 34 which are normally closed) and bit 0 to 1 (Servo On mask time always enabled).

 

[derekmccoy]

@masso-support
The last two parameter changes in my previous post have raised some questions for me. How does Masso know the servo realtime position and if the servo has finished its positioning? Should the 'positioning complete' signal be sent back to Masso?

@breezy
Looking at the manual again, I have some confusion.
Pins 28 and 29 are now set to pulse with 47 as their ground
Pins 26 and 27 are now direction with 48 as their ground
The figure showing the CN1 pinout for the code+pulse train pins shows what looks like a NOT gate but with two outputs. I don't know if this means I have to first invert pins 27 and 29 before they go into CN1?

 

[breezy]

Derek,

The figure showing the CN1 pinout for the code+pulse train pins shows what looks like a NOT gate but with two outputs.

That is a differential output symbol.

I don't know if this means I have to first invert pins 27 and 29 before they go into CN1?

MASSO axis outputs are differential so connect the pins as follows

1. S+ -> CN1 28
   
2. S- -> CN1 29
   
3. D+ -> CN1 26
   
4. D- -> CN1 27
   

Common up CN1 48,49 to MASSO -ve

Read up on Axis Servo/Stepper examples, in the documentation you will see that some drives require both output pins connected and others only require the +ve pin and gnd connections.

Regards,

Arie.

 

[masso-support]

Quote from derekmccoy on May 24, 2020, 2:21 am

@masso-support
The last two parameter changes in my previous post have raised some questions for me. How does Masso know the servo realtime position and if the servo has finished its positioning? Should the 'positioning complete' signal be sent back to Masso?

Masso does not use the position complete signal. It simply sends the required direction and number of pulses to the servo to get the servo to the desired location, the servo does the rest. If the servo has an issue it sends an alarm back to Masso.

Cheers Peter

 

[derekmccoy]

G3 arrived yesterday. I'm gonna wire it up tomorrow to a single axis and do a jog test.

@breezy
The PY2 manual say that for the position command input, the "current limit input" should be 2.0 VDC 15% (at rated armature current). Do I just wire it up directly or do I have to do anything to meet these limits?

 

[breezy]

Derek,

The PY2 manual say that for the position command input, the "current limit input" should be 2.0 VDC 15% (at rated armature current)

This had me beat for awhile, so did search of PDF for "current limit input" and finally found an explanation at Section 9 (3) External analog current limit input, this has nothing to do with MASSO step & direction signals. So just wire up and enjoy using your machine.

Regards,

Arie.

 

[derekmccoy]

Ok I ve wired up the Y axis to test. Checked continuity and it all seems to be in the right place.
However I cannot jog the motor. Simply no movement. I thought just wiring it up and hitting go was too simple so there must be more to it.....

I've gone back to the manual and the wiring section on pages 4-5, 4-6 and 4-7 mention much more than just the 6 pins I wired.
Also, there is a TON of settings that can be made to the amplifier regarding position control. There's stuff that's way beyond me like pulse width, position loop gain, cutoff frequency for low pass filter, LPF time constant, etc. It's a bit of a minefield and I don't know if any of those are the reason the motors are not jogging.

It would be good if @masso-support could help me out here. If it weren't for @breezy I wouldn't have gotten anywhere with this. Thanks

 

[derekmccoy]

@breezy

Sorry to bother you again, Arie.

In the wiring section of the manual, page 4-5 mentions something about choosing a power supply, either 5v or 12-24v and connecting it to pins 38 or 49 respectively. Could this be the reason they are not working?

Also, page 4-6 shows a diagram which is different to the pinout I soldered. It doesn't mention pins 27 and 29.

And just to add to the complexity, page 9-33 (General Specifications of Position Control Type Input Signals) mentions a "Servo On - Servo ON status is provided by closing the contact, and entering the pulse train waiting status." Do I have to short these pins?

Any help is appreciated to get these going. I don't know what to do apart from trying to find a servo engineer who has experience with these amplifiers.

Thanks,
Derek

 

[breezy]

Derek,

In the wiring section of the manual, page 4-5 mentions something about choosing a power supply, either 5v or 12-24v and connecting it to pins 38 or 49 respectively. Could this be the reason they are not working?

Applying 5v to 38 or 12v-24v to 49 and -ve to 24,25 "turns on" the output signal pins 39-46 by providing power to the optocouplers, so that won't stop it from working.

Also, page 4-6 shows a diagram which is different to the pinout I soldered. It doesn't mention pins 27 and 29.

What you wired up is differential output which is more noise resistant than a single output with common ground. S o don't worry about that diagram.

And just to add to the complexity, page 9-33 (General Specifications of Position Control Type Input Signals) mentions a "Servo On - Servo ON status is provided by closing the contact, and entering the pulse train waiting status." Do I have to short these pins?

Now I said in post #2 You may need to connect other pins to "enable" the drive, which you should be able to work out from the information in the PDF. To achieve this apply +ve to pin 23 and -ve to 37. This should help to get you running. There maybe parameters to set to the driver working in S & D mode, but I think the changes you listed are all that are required.

Regards,

Arie.

 

[derekmccoy]

Quote from Breezy on June 4, 2020, 9:08 pm

Now I said in post #2 You may need to connect other pins to "enable" the drive, which you should be able to work out from the information in the PDF. To achieve this apply +ve to pin 23 and -ve to 37. This should help to get you running. There maybe parameters to set to the driver working in S & D mode, but I think the changes you listed are all that are required.

Thanks for this, Arie. I wired up the Servo On pins as you said but unfortunately it did not make a difference. The amp has a 7 segment LED and it's meant to turn into a figure of 8 when Servo On is enabled (as mentioned on page 6-8). It remained with the middle line LED which is "The control power supply (r, t) is set up and the amplifier ready output (RDY) signal is ON".

I thought this was the end of the road, however I did some troubleshooting. I plugged the amplifier back into the old controller's PCB and powered the table up. The 7 segment LED showed the middle line as before. However when I pressed the start-up button on the old CNC controller, I saw the figure of 8 on the 7 segment LED (obviously, this is expected). This is telling me there is more than just the Servo On pins involved to get the amp to show "Servo On".
Now, CN1 is split into 2 connectors on the old PCB, the left hand side one goes to the Servo On pins. Unplugging the right half does not seem to make a difference. Unplugging the left hand connector turns off the "Servo On" (figure of 8) so the left hand connector seems to hold the key.

There are another 6 wires (8 total) in the left hand connector:

Green	37	Servo On (SON)
Yellow	30	Alarm Reset (RST)
Pink/White	41	Operation Ready Complete (SRDY)
Pink/Brown	24	Output Sequence Power Common
Red/Blue	49	Output Sequence power supply. External power supply for CN1-39, 40, 41 (SRDY), 42, 43, 44, 45 and 46.
Green/White	23	Input sequence power supply 1. External power supply for CN1-30 (RST), 31, 32 (PROT), 33 (NROT), 36 and 37 (SON)
Yellow/Brown	33	Backward rev side overtravel (NROT)
Yellow/White	32	Forward rev side overtravel (PROT) **CN1 schematic says 'fw pulse command' but this is a typo**

I don't understand why the manual says pin 37 (Servo On) has it's ground as pin 23 (input seq ps 1), but pin 41 (SRDY) has its ground as pin 24 (out seq com) and at the same time also has pin 49 (out seq ps).

My brain says start disconnecting wires until the amp stops showing Servo On and that will tell me which is the one that I need to enable. Not sure that's a good way to proceed though.

@breezy is there anything there that you can spot as an obvious? Again, your help is very much appreciated.