Re: [Emc-users] Mesa Card Stepgens?

[Peter Wallace]

On Fri, 10 May 2024, John Dammeyer wrote:


Date: Fri, 10 May 2024 18:26:21 -0700
From: John Dammeyer 
Reply-To: "Enhanced Machine Controller (EMC)"

To: "'Enhanced Machine Controller (EMC)'" 
Subject: Re: [Emc-users] Mesa Card Stepgens?

What type of output driver is used on the 7i84?
John


The 7I84/7I84D use the  (now obsolete) NCV7608
It has flyback protection (turnoff speed modulation)
but that's only good to ~60 mA so for more you need
flyback diodes

It, replacement (7I84U) uses the NCV7224

The 7724 is a bit nicer as it can do sink,source,
or push-pull under software control
(and 350 mA on inductive or non-inductive loads with no flyback diodes)




-Original Message-
From: Peter Wallace [mailto:p...@mesanet.com]
Sent: May 10, 2024 1:54 PM
To: Todd Zuercher
Cc: Todd Zuercher via Emc-users
Subject: Re: [Emc-users] Mesa Card Stepgens?

On Fri, 10 May 2024, Todd Zuercher wrote:


Date: Fri, 10 May 2024 20:40:53 +
From: Todd Zuercher 
To: Peter Wallace 
Cc: Todd Zuercher via Emc-users 
Subject: RE: [Emc-users] Mesa Card Stepgens?

Peter,

I've ran into another bit of a snag.  I have a couple of 24v relays from
Automationdirect.  The resistance on the coils is about 635ohms.  I

thought

that the outputs on the 7i84 were supposed to be ok with running a small
relay with up to about 40mA without needing a flyback diode.  It's close

but

just under that.  Well, I've managed to kill 3 of the outputs with those
relays (the outputs are stuck always on).  I've put a couple of diodes

on

the relay coils, I hope that works and I don't ruin any more.  What does

it

take to replace the chip or chips that would be damaged by this?


40 mA should be fine, it is possible this is the card that had power

applied

backwards?

We can replace the chips



Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Peter Wallace 
Sent: Monday, April 15, 2024 5:09 PM
To: Todd Zuercher 
Cc: Todd Zuercher via Emc-users 
Subject: RE: [Emc-users] Mesa Card Stepgens?

[EXTERNAL EMAIL] Be sure links are safe.

On Mon, 15 Apr 2024, Todd Zuercher wrote:


Date: Mon, 15 Apr 2024 20:22:03 +
From: Todd Zuercher 
To: Peter Wallace ,
Todd Zuercher via Emc-users 
Subject: RE: [Emc-users] Mesa Card Stepgens?

Thanks Peter,

We've had this 7i85s for quite a while, and it must be one of the
early ones because I see DS34C87TM chips on it.

I'm not sure I like the idea of using them single ended.  But is a
+5v-0v single ended signal actually any better or even much different
than a +/-3v differential signal?  How hard would it be to move the
last steepen over to the 7i88 and have all 8 of these stepgens on one
card?  I am not planning on using the Smart Serial output on the 7i88.
The 3 servos have been working on the 7i85S for years and can stay

there.


Differential is needed and advised for servo drives with line receiver

inputs,

however, with optocoupled input step/dir drives, there is little advantage

to

differential mode. With optocoupled input step/dir drives the input will

only

see ~3V drive in differential mode with the DS34C87 driver, so its better

to

run in single ended mode with the 7I85S sinking so you get full 5V drive.




I am using the Smart Serial connection on the 7i85s to connect a 7i84.

If all else fails I can simply set all of the other steppers the same
as the slow one and leave it be.  Even the slow one is working as fast
or faster than I was hoping it would, but a little more safety margin

would

be nice.


The drives are likely not rated for 3V input so you would probably be

better

off if you ran single ended.





Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Peter Wallace 
Sent: Monday, April 15, 2024 3:41 PM
To: Todd Zuercher via Emc-users 
Cc: Todd Zuercher 
Subject: Re: [Emc-users] Mesa Card Stepgens?

[EXTERNAL EMAIL] Be sure links are safe.

On Mon, 15 Apr 2024, Todd Zuercher via Emc-users wrote:


Date: Mon, 15 Apr 2024 19:27:19 +
From: Todd Zuercher via Emc-users 
To: "Enhanced Machine Controller (EMC)"

Cc: Todd Zuercher 
Subject: [Emc-users] Mesa Card Stepgens?

I was working on this machine where I need a whole bunch of extra

stepgens.  I am using a Mesa 7i85S and a 7i88 connected to a 5i25 card.  I

was

testing some of the stepper drives and I noticed that with one of the
drive/motor combinations I am needing to use slightly longer step timing

and

lower max velocity.  I thought that this was odd, because all of the

drives,

motors, and mechanicals are the same for all of the ones I was testing.

The

only difference is that the slower one was connected to a stepgen on the
7i85S and all of the others are on the 7i88.  So just for curiosity sake I

checked

the voltage at the input terminals of step/dir signals of the drive.  On

the

terminals conne

Re: [Emc-users] Mesa Card Stepgens?

[John Dammeyer]

What type of output driver is used on the 7i84?
John

> -Original Message-
> From: Peter Wallace [mailto:p...@mesanet.com]
> Sent: May 10, 2024 1:54 PM
> To: Todd Zuercher
> Cc: Todd Zuercher via Emc-users
> Subject: Re: [Emc-users] Mesa Card Stepgens?
> 
> On Fri, 10 May 2024, Todd Zuercher wrote:
> 
> > Date: Fri, 10 May 2024 20:40:53 +
> > From: Todd Zuercher 
> > To: Peter Wallace 
> > Cc: Todd Zuercher via Emc-users 
> > Subject: RE: [Emc-users] Mesa Card Stepgens?
> >
> > Peter,
> >
> > I've ran into another bit of a snag.  I have a couple of 24v relays from
> > Automationdirect.  The resistance on the coils is about 635ohms.  I
thought
> > that the outputs on the 7i84 were supposed to be ok with running a small
> > relay with up to about 40mA without needing a flyback diode.  It's close
but
> > just under that.  Well, I've managed to kill 3 of the outputs with those
> > relays (the outputs are stuck always on).  I've put a couple of diodes
on
> > the relay coils, I hope that works and I don't ruin any more.  What does
it
> > take to replace the chip or chips that would be damaged by this?
> 
> 40 mA should be fine, it is possible this is the card that had power
applied
> backwards?
> 
> We can replace the chips
> 
> >
> > Todd Zuercher
> > P. Graham Dunn Inc.
> > 630 Henry Street
> > Dalton, Ohio 44618
> > Phone:  (330)828-2105ext. 2031
> >
> > -----Original Message-
> > From: Peter Wallace 
> > Sent: Monday, April 15, 2024 5:09 PM
> > To: Todd Zuercher 
> > Cc: Todd Zuercher via Emc-users 
> > Subject: RE: [Emc-users] Mesa Card Stepgens?
> >
> > [EXTERNAL EMAIL] Be sure links are safe.
> >
> > On Mon, 15 Apr 2024, Todd Zuercher wrote:
> >
> >> Date: Mon, 15 Apr 2024 20:22:03 +
> >> From: Todd Zuercher 
> >> To: Peter Wallace ,
> >> Todd Zuercher via Emc-users 
> >> Subject: RE: [Emc-users] Mesa Card Stepgens?
> >>
> >> Thanks Peter,
> >>
> >> We've had this 7i85s for quite a while, and it must be one of the
> >> early ones because I see DS34C87TM chips on it.
> >>
> >> I'm not sure I like the idea of using them single ended.  But is a
> >> +5v-0v single ended signal actually any better or even much different
> >> than a +/-3v differential signal?  How hard would it be to move the
> >> last steepen over to the 7i88 and have all 8 of these stepgens on one
> >> card?  I am not planning on using the Smart Serial output on the 7i88.
> >> The 3 servos have been working on the 7i85S for years and can stay
there.
> >
> > Differential is needed and advised for servo drives with line receiver
inputs,
> however, with optocoupled input step/dir drives, there is little advantage
to
> differential mode. With optocoupled input step/dir drives the input will
only
> see ~3V drive in differential mode with the DS34C87 driver, so its better
to
> run in single ended mode with the 7I85S sinking so you get full 5V drive.
> >
> >>
> >> I am using the Smart Serial connection on the 7i85s to connect a 7i84.
> >>
> >> If all else fails I can simply set all of the other steppers the same
> >> as the slow one and leave it be.  Even the slow one is working as fast
> >> or faster than I was hoping it would, but a little more safety margin
would
> be nice.
> >
> > The drives are likely not rated for 3V input so you would probably be
better
> off if you ran single ended.
> >
> >
> >>
> >> Todd Zuercher
> >> P. Graham Dunn Inc.
> >> 630 Henry Street
> >> Dalton, Ohio 44618
> >> Phone:  (330)828-2105ext. 2031
> >>
> >> -Original Message-
> >> From: Peter Wallace 
> >> Sent: Monday, April 15, 2024 3:41 PM
> >> To: Todd Zuercher via Emc-users 
> >> Cc: Todd Zuercher 
> >> Subject: Re: [Emc-users] Mesa Card Stepgens?
> >>
> >> [EXTERNAL EMAIL] Be sure links are safe.
> >>
> >> On Mon, 15 Apr 2024, Todd Zuercher via Emc-users wrote:
> >>
> >>> Date: Mon, 15 Apr 2024 19:27:19 +
> >>> From: Todd Zuercher via Emc-users 
> >>> To: "Enhanced Machine Controller (EMC)"
> >>> 
> >>> Cc: Todd Zuercher 
> >>> Subject: [Emc-users] Mesa Card Stepgens?
> >>>
> >>> I was working on this machine where I need a whole bunch of extra
> stepgens.  I am using a Mesa 7i85S and a 7i88 connected to a 5i25 card.  I
was
> testing some of

Re: [Emc-users] Mesa Card Stepgens?

[Todd Zuercher via Emc-users]

Peter,

I've ran into another bit of a snag.  I have a couple of 24v relays from 
Automationdirect.  The resistance on the coils is about 635ohms.  I thought 
that the outputs on the 7i84 were supposed to be ok with running a small relay 
with up to about 40mA without needing a flyback diode.  It's close but just 
under that.  Well, I've managed to kill 3 of the outputs with those relays (the 
outputs are stuck always on).  I've put a couple of diodes on the relay coils, 
I hope that works and I don't ruin any more.  What does it take to replace the 
chip or chips that would be damaged by this?

Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Peter Wallace 
Sent: Monday, April 15, 2024 5:09 PM
To: Todd Zuercher 
Cc: Todd Zuercher via Emc-users 
Subject: RE: [Emc-users] Mesa Card Stepgens?

[EXTERNAL EMAIL] Be sure links are safe.

On Mon, 15 Apr 2024, Todd Zuercher wrote:

> Date: Mon, 15 Apr 2024 20:22:03 +
> From: Todd Zuercher 
> To: Peter Wallace ,
> Todd Zuercher via Emc-users 
> Subject: RE: [Emc-users] Mesa Card Stepgens?
>
> Thanks Peter,
>
> We've had this 7i85s for quite a while, and it must be one of the
> early ones because I see DS34C87TM chips on it.
>
> I'm not sure I like the idea of using them single ended.  But is a
> +5v-0v single ended signal actually any better or even much different
> than a +/-3v differential signal?  How hard would it be to move the
> last steepen over to the 7i88 and have all 8 of these stepgens on one
> card?  I am not planning on using the Smart Serial output on the 7i88.
> The 3 servos have been working on the 7i85S for years and can stay there.

Differential is needed and advised for servo drives with line receiver inputs, 
however, with optocoupled input step/dir drives, there is little advantage to 
differential mode. With optocoupled input step/dir drives the input will only 
see ~3V drive in differential mode with the DS34C87 driver, so its better to 
run in single ended mode with the 7I85S sinking so you get full 5V drive.

>
> I am using the Smart Serial connection on the 7i85s to connect a 7i84.
>
> If all else fails I can simply set all of the other steppers the same
> as the slow one and leave it be.  Even the slow one is working as fast
> or faster than I was hoping it would, but a little more safety margin would 
> be nice.

The drives are likely not rated for 3V input so you would probably be better 
off if you ran single ended.


>
> Todd Zuercher
> P. Graham Dunn Inc.
> 630 Henry Street
> Dalton, Ohio 44618
> Phone:  (330)828-2105ext. 2031
>
> -Original Message-
> From: Peter Wallace 
> Sent: Monday, April 15, 2024 3:41 PM
> To: Todd Zuercher via Emc-users 
> Cc: Todd Zuercher 
> Subject: Re: [Emc-users] Mesa Card Stepgens?
>
> [EXTERNAL EMAIL] Be sure links are safe.
>
> On Mon, 15 Apr 2024, Todd Zuercher via Emc-users wrote:
>
>> Date: Mon, 15 Apr 2024 19:27:19 +0000
>> From: Todd Zuercher via Emc-users 
>> To: "Enhanced Machine Controller (EMC)"
>> 
>> Cc: Todd Zuercher 
>> Subject: [Emc-users] Mesa Card Stepgens?
>>
>> I was working on this machine where I need a whole bunch of extra stepgens.  
>> I am using a Mesa 7i85S and a 7i88 connected to a 5i25 card.  I was testing 
>> some of the stepper drives and I noticed that with one of the drive/motor 
>> combinations I am needing to use slightly longer step timing and lower max 
>> velocity.  I thought that this was odd, because all of the drives, motors, 
>> and mechanicals are the same for all of the ones I was testing.  The only 
>> difference is that the slower one was connected to a stepgen on the 7i85S 
>> and all of the others are on the 7i88.  So just for curiosity sake I checked 
>> the voltage at the input terminals of step/dir signals of the drive.  On the 
>> terminals connected to the 7i88 I found +/-5v, and on the one connected to 
>> the 7i85S there is only +/-3v.  This is the only difference I've been able 
>> to find between the different joints in question.
>>
>> Does it make sense that the voltages would be different on the step/dir 
>> outputs between the 7i85s and the 7i88?  Does it make sense that the 
>> difference would cause a difference in the required step timing?  Why might 
>> there be a difference between the output voltage on the two cards?
>>
>> Both cards are getting their 5v from the 5i25.  The 7i85S is also connected 
>> to 3 step/gen servo drives and their encoder's feedbacks.  Is it possible 
>> that the 5v drain from the encoders might be causing the lower voltage on 
>> the 7i85S's outputs?
>
>
> I would check the 5V rail at the 7I85S card

Re: [Emc-users] Mesa Card Stepgens?

[Peter Wallace]

On Fri, 10 May 2024, Todd Zuercher wrote:


Date: Fri, 10 May 2024 20:40:53 +
From: Todd Zuercher 
To: Peter Wallace 
Cc: Todd Zuercher via Emc-users 
Subject: RE: [Emc-users] Mesa Card Stepgens?

Peter,

I've ran into another bit of a snag.  I have a couple of 24v relays from 
Automationdirect.  The resistance on the coils is about 635ohms.  I thought 
that the outputs on the 7i84 were supposed to be ok with running a small 
relay with up to about 40mA without needing a flyback diode.  It's close but 
just under that.  Well, I've managed to kill 3 of the outputs with those 
relays (the outputs are stuck always on).  I've put a couple of diodes on 
the relay coils, I hope that works and I don't ruin any more.  What does it 
take to replace the chip or chips that would be damaged by this?


40 mA should be fine, it is possible this is the card that had power applied 
backwards?


We can replace the chips



Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Peter Wallace 
Sent: Monday, April 15, 2024 5:09 PM
To: Todd Zuercher 
Cc: Todd Zuercher via Emc-users 
Subject: RE: [Emc-users] Mesa Card Stepgens?

[EXTERNAL EMAIL] Be sure links are safe.

On Mon, 15 Apr 2024, Todd Zuercher wrote:


Date: Mon, 15 Apr 2024 20:22:03 +
From: Todd Zuercher 
To: Peter Wallace ,
Todd Zuercher via Emc-users 
Subject: RE: [Emc-users] Mesa Card Stepgens?

Thanks Peter,

We've had this 7i85s for quite a while, and it must be one of the
early ones because I see DS34C87TM chips on it.

I'm not sure I like the idea of using them single ended.  But is a
+5v-0v single ended signal actually any better or even much different
than a +/-3v differential signal?  How hard would it be to move the
last steepen over to the 7i88 and have all 8 of these stepgens on one
card?  I am not planning on using the Smart Serial output on the 7i88.
The 3 servos have been working on the 7i85S for years and can stay there.


Differential is needed and advised for servo drives with line receiver inputs, 
however, with optocoupled input step/dir drives, there is little advantage to 
differential mode. With optocoupled input step/dir drives the input will only 
see ~3V drive in differential mode with the DS34C87 driver, so its better to 
run in single ended mode with the 7I85S sinking so you get full 5V drive.



I am using the Smart Serial connection on the 7i85s to connect a 7i84.

If all else fails I can simply set all of the other steppers the same
as the slow one and leave it be.  Even the slow one is working as fast
or faster than I was hoping it would, but a little more safety margin would be 
nice.


The drives are likely not rated for 3V input so you would probably be better 
off if you ran single ended.




Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Peter Wallace 
Sent: Monday, April 15, 2024 3:41 PM
To: Todd Zuercher via Emc-users 
Cc: Todd Zuercher 
Subject: Re: [Emc-users] Mesa Card Stepgens?

[EXTERNAL EMAIL] Be sure links are safe.

On Mon, 15 Apr 2024, Todd Zuercher via Emc-users wrote:


Date: Mon, 15 Apr 2024 19:27:19 +
From: Todd Zuercher via Emc-users 
To: "Enhanced Machine Controller (EMC)"

Cc: Todd Zuercher 
Subject: [Emc-users] Mesa Card Stepgens?

I was working on this machine where I need a whole bunch of extra stepgens.  I 
am using a Mesa 7i85S and a 7i88 connected to a 5i25 card.  I was testing some 
of the stepper drives and I noticed that with one of the drive/motor 
combinations I am needing to use slightly longer step timing and lower max 
velocity.  I thought that this was odd, because all of the drives, motors, and 
mechanicals are the same for all of the ones I was testing.  The only 
difference is that the slower one was connected to a stepgen on the 7i85S and 
all of the others are on the 7i88.  So just for curiosity sake I checked the 
voltage at the input terminals of step/dir signals of the drive.  On the 
terminals connected to the 7i88 I found +/-5v, and on the one connected to the 
7i85S there is only +/-3v.  This is the only difference I've been able to find 
between the different joints in question.

Does it make sense that the voltages would be different on the step/dir outputs 
between the 7i85s and the 7i88?  Does it make sense that the difference would 
cause a difference in the required step timing?  Why might there be a 
difference between the output voltage on the two cards?

Both cards are getting their 5v from the 5i25.  The 7i85S is also connected to 
3 step/gen servo drives and their encoder's feedbacks.  Is it possible that the 
5v drain from the encoders might be causing the lower voltage on the 7i85S's 
outputs?



I would check the 5V rail at the 7I85S card, and if its low, power the
7I85S directly from 5V rather the through the parallel cable. ALso the
very first lot (many years ago) of 7I85S 

Re: [Emc-users] Mesa Card Stepgens?

[gene heskett]

On 4/15/24 17:09, Peter Wallace wrote:

On Mon, 15 Apr 2024, Todd Zuercher wrote:


Date: Mon, 15 Apr 2024 20:22:03 +
From: Todd Zuercher 
To: Peter Wallace ,
    Todd Zuercher via Emc-users 
Subject: RE: [Emc-users] Mesa Card Stepgens?

Thanks Peter,

We've had this 7i85s for quite a while, and it must be one of the 
early ones because I see DS34C87TM chips on it.


I'm not sure I like the idea of using them single ended.  But is a 
+5v-0v single ended signal actually any better or even much different 
than a +/-3v differential signal?  How hard would it be to move the 
last steepen over to the 7i88 and have all 8 of these stepgens on one 
card?  I am not planning on using the Smart Serial output on the 
7i88.  The 3 servos have been working on the 7i85S for years and can 
stay there.


Differential is needed and advised for servo drives with line receiver 
inputs,
however, with optocoupled input step/dir drives, there is little 
advantage to differential mode. With optocoupled input step/dir drives 
the input will only see ~3V drive in differential mode with the DS34C87 
driver, so its better to run in single ended mode with the 7I85S sinking 
so you get full 5V drive.




I am using the Smart Serial connection on the 7i85s to connect a 7i84.

If all else fails I can simply set all of the other steppers the same 
as the slow one and leave it be.  Even the slow one is working as fast 
or faster than I was hoping it would, but a little more safety margin 
would be nice.


The drives are likely not rated for 3V input so you would probably be 
better off if you ran single ended.


I'm running into the same problem in 3d printers, Peter. I am currently 
rebuilding an Ender5+ using the new stepper/servo drives from hanpose, 
that are rated for up to 90 volts for the nema 17 motors used on most 
printers. Most of the big tree tech controller boards use 1.5 micro-sec 
step pulses, but I am finding I need to stretch that to 2 micro-secs if 
I don't want an occasional miss, this while driving the lc42 driver. 
These drivers all have opto inputs, and need a little longer step on the 
less than 5 volt signals.



Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Peter Wallace 
Sent: Monday, April 15, 2024 3:41 PM
To: Todd Zuercher via Emc-users 
Cc: Todd Zuercher 
Subject: Re: [Emc-users] Mesa Card Stepgens?

[EXTERNAL EMAIL] Be sure links are safe.

On Mon, 15 Apr 2024, Todd Zuercher via Emc-users wrote:


Date: Mon, 15 Apr 2024 19:27:19 +
From: Todd Zuercher via Emc-users 
To: "Enhanced Machine Controller (EMC)"

Cc: Todd Zuercher 
Subject: [Emc-users] Mesa Card Stepgens?

I was working on this machine where I need a whole bunch of extra 
stepgens.  I am using a Mesa 7i85S and a 7i88 connected to a 5i25 
card.  I was testing some of the stepper drives and I noticed that 
with one of the drive/motor combinations I am needing to use slightly 
longer step timing and lower max velocity.  I thought that this was 
odd, because all of the drives, motors, and mechanicals are the same 
for all of the ones I was testing.  The only difference is that the 
slower one was connected to a stepgen on the 7i85S and all of the 
others are on the 7i88.  So just for curiosity sake I checked the 
voltage at the input terminals of step/dir signals of the drive.  On 
the terminals connected to the 7i88 I found +/-5v, and on the one 
connected to the 7i85S there is only +/-3v.  This is the only 
difference I've been able to find between the different joints in 
question.


Does it make sense that the voltages would be different on the 
step/dir outputs between the 7i85s and the 7i88?  Does it make sense 
that the difference would cause a difference in the required step 
timing?  Why might there be a difference between the output voltage 
on the two cards?


Both cards are getting their 5v from the 5i25.  The 7i85S is also 
connected to 3 step/gen servo drives and their encoder's feedbacks.  
Is it possible that the 5v drain from the encoders might be causing 
the lower voltage on the 7i85S's outputs?



I would check the 5V rail at the 7I85S card, and if its low, power the 
7I85S directly from 5V rather the through the parallel cable. ALso the 
very first lot (many years ago) of 7I85S cards were built with DS34C87 
drivers which do not have full 5V drive. If you have this card, you 
can get 5V drive by using single ended sinking outputs and 5V+ to 
drive step+ and 7i85s step- to drive

step-



Todd Zuercher
P. Graham Dunn
Inc.<https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2F
www.pgrahamdunn.com%2Findex.php=05%7C02%7Ctoddz%40pgrahamdunn.com
%7Cc87909c9a4b6452a9e7008dc5d83f6a5%7C5758544c573f47cebee96c3e0806fb43
%7C0%7C0%7C638488068569795566%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAw
MDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C=
%2BkgiY%2FC9l6%2BqT2O6bnpxqPKur7Myu6%2BaULa01B910Ck%3D=0>
630 Hen

Re: [Emc-users] Mesa Card Stepgens?

[Peter Wallace]

On Mon, 15 Apr 2024, Todd Zuercher wrote:


Date: Mon, 15 Apr 2024 20:22:03 +
From: Todd Zuercher 
To: Peter Wallace ,
Todd Zuercher via Emc-users 
Subject: RE: [Emc-users] Mesa Card Stepgens?

Thanks Peter,

We've had this 7i85s for quite a while, and it must be one of the early ones 
because I see DS34C87TM chips on it.


I'm not sure I like the idea of using them single ended.  But is a +5v-0v 
single ended signal actually any better or even much different than a +/-3v 
differential signal?  How hard would it be to move the last steepen over to 
the 7i88 and have all 8 of these stepgens on one card?  I am not planning on 
using the Smart Serial output on the 7i88.  The 3 servos have been working 
on the 7i85S for years and can stay there.


Differential is needed and advised for servo drives with line receiver inputs,
however, with optocoupled input step/dir drives, there is little advantage to 
differential mode. With optocoupled input step/dir drives the input will only 
see ~3V drive in differential mode with the DS34C87 driver, so its better to 
run in single ended mode with the 7I85S sinking so you get full 5V drive.




I am using the Smart Serial connection on the 7i85s to connect a 7i84.

If all else fails I can simply set all of the other steppers the same as the 
slow one and leave it be.  Even the slow one is working as fast or faster 
than I was hoping it would, but a little more safety margin would be nice.


The drives are likely not rated for 3V input so you would probably be better 
off if you ran single ended.





Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street 
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Peter Wallace 
Sent: Monday, April 15, 2024 3:41 PM
To: Todd Zuercher via Emc-users 
Cc: Todd Zuercher 
Subject: Re: [Emc-users] Mesa Card Stepgens?

[EXTERNAL EMAIL] Be sure links are safe.

On Mon, 15 Apr 2024, Todd Zuercher via Emc-users wrote:


Date: Mon, 15 Apr 2024 19:27:19 +
From: Todd Zuercher via Emc-users 
To: "Enhanced Machine Controller (EMC)"

Cc: Todd Zuercher 
Subject: [Emc-users] Mesa Card Stepgens?

I was working on this machine where I need a whole bunch of extra stepgens.  I 
am using a Mesa 7i85S and a 7i88 connected to a 5i25 card.  I was testing some 
of the stepper drives and I noticed that with one of the drive/motor 
combinations I am needing to use slightly longer step timing and lower max 
velocity.  I thought that this was odd, because all of the drives, motors, and 
mechanicals are the same for all of the ones I was testing.  The only 
difference is that the slower one was connected to a stepgen on the 7i85S and 
all of the others are on the 7i88.  So just for curiosity sake I checked the 
voltage at the input terminals of step/dir signals of the drive.  On the 
terminals connected to the 7i88 I found +/-5v, and on the one connected to the 
7i85S there is only +/-3v.  This is the only difference I've been able to find 
between the different joints in question.

Does it make sense that the voltages would be different on the step/dir outputs 
between the 7i85s and the 7i88?  Does it make sense that the difference would 
cause a difference in the required step timing?  Why might there be a 
difference between the output voltage on the two cards?

Both cards are getting their 5v from the 5i25.  The 7i85S is also connected to 
3 step/gen servo drives and their encoder's feedbacks.  Is it possible that the 
5v drain from the encoders might be causing the lower voltage on the 7i85S's 
outputs?



I would check the 5V rail at the 7I85S card, and if its low, power the 7I85S 
directly from 5V rather the through the parallel cable. ALso the very first lot 
(many years ago) of 7I85S cards were built with DS34C87 drivers which do not 
have full 5V drive. If you have this card, you can get 5V drive by using single 
ended sinking outputs and 5V+ to drive step+ and 7i85s step- to drive
step-



Todd Zuercher
P. Graham Dunn
Inc.<https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2F
www.pgrahamdunn.com%2Findex.php=05%7C02%7Ctoddz%40pgrahamdunn.com
%7Cc87909c9a4b6452a9e7008dc5d83f6a5%7C5758544c573f47cebee96c3e0806fb43
%7C0%7C0%7C638488068569795566%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAw
MDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C=
%2BkgiY%2FC9l6%2BqT2O6bnpxqPKur7Myu6%2BaULa01B910Ck%3D=0>
630 Henry Street
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031


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Re: [Emc-users] Mesa Card Stepgens?

[Todd Zuercher via Emc-users]

Thanks Peter,

We've had this 7i85s for quite a while, and it must be one of the early ones 
because I see DS34C87TM chips on it.

I'm not sure I like the idea of using them single ended.  But is a +5v-0v 
single ended signal actually any better or even much different than a +/-3v 
differential signal?  How hard would it be to move the last steepen  over to 
the 7i88 and have all 8 of these stepgens on one card?  I am not planning on 
using the Smart Serial output on the 7i88.  The 3 servos have been working on 
the 7i85S for years and can stay there.

I am using the Smart Serial connection on the 7i85s to connect a 7i84.

If all else fails I can simply set all of the other steppers the same as the 
slow one and leave it be.  Even the slow one is working as fast or faster than 
I was hoping it would, but a little more safety margin would be nice.

Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street 
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Peter Wallace  
Sent: Monday, April 15, 2024 3:41 PM
To: Todd Zuercher via Emc-users 
Cc: Todd Zuercher 
Subject: Re: [Emc-users] Mesa Card Stepgens?

[EXTERNAL EMAIL] Be sure links are safe.

On Mon, 15 Apr 2024, Todd Zuercher via Emc-users wrote:

> Date: Mon, 15 Apr 2024 19:27:19 +
> From: Todd Zuercher via Emc-users 
> To: "Enhanced Machine Controller (EMC)" 
> 
> Cc: Todd Zuercher 
> Subject: [Emc-users] Mesa Card Stepgens?
>
> I was working on this machine where I need a whole bunch of extra stepgens.  
> I am using a Mesa 7i85S and a 7i88 connected to a 5i25 card.  I was testing 
> some of the stepper drives and I noticed that with one of the drive/motor 
> combinations I am needing to use slightly longer step timing and lower max 
> velocity.  I thought that this was odd, because all of the drives, motors, 
> and mechanicals are the same for all of the ones I was testing.  The only 
> difference is that the slower one was connected to a stepgen on the 7i85S and 
> all of the others are on the 7i88.  So just for curiosity sake I checked the 
> voltage at the input terminals of step/dir signals of the drive.  On the 
> terminals connected to the 7i88 I found +/-5v, and on the one connected to 
> the 7i85S there is only +/-3v.  This is the only difference I've been able to 
> find between the different joints in question.
>
> Does it make sense that the voltages would be different on the step/dir 
> outputs between the 7i85s and the 7i88?  Does it make sense that the 
> difference would cause a difference in the required step timing?  Why might 
> there be a difference between the output voltage on the two cards?
>
> Both cards are getting their 5v from the 5i25.  The 7i85S is also connected 
> to 3 step/gen servo drives and their encoder's feedbacks.  Is it possible 
> that the 5v drain from the encoders might be causing the lower voltage on the 
> 7i85S's outputs?


I would check the 5V rail at the 7I85S card, and if its low, power the 7I85S 
directly from 5V rather the through the parallel cable. ALso the very first lot 
(many years ago) of 7I85S cards were built with DS34C87 drivers which do not 
have full 5V drive. If you have this card, you can get 5V drive by using single 
ended sinking outputs and 5V+ to drive step+ and 7i85s step- to drive
step-

>
> Todd Zuercher
> P. Graham Dunn 
> Inc.<https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2F
> www.pgrahamdunn.com%2Findex.php=05%7C02%7Ctoddz%40pgrahamdunn.com
> %7Cc87909c9a4b6452a9e7008dc5d83f6a5%7C5758544c573f47cebee96c3e0806fb43
> %7C0%7C0%7C638488068569795566%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAw
> MDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C=
> %2BkgiY%2FC9l6%2BqT2O6bnpxqPKur7Myu6%2BaULa01B910Ck%3D=0>
> 630 Henry Street
> Dalton, Ohio 44618
> Phone:  (330)828-2105ext. 2031
>
>
> ___
> Emc-users mailing list
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> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Flist
> s.sourceforge.net%2Flists%2Flistinfo%2Femc-users=05%7C02%7Ctoddz%
> 40pgrahamdunn.com%7Cc87909c9a4b6452a9e7008dc5d83f6a5%7C5758544c573f47c
> ebee96c3e0806fb43%7C0%7C0%7C638488068569804807%7CUnknown%7CTWFpbGZsb3d
> 8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C
> 0%7C%7C%7C=sb3DbNBIrWxq9OqYRv32Q6KHka%2FvXqAzp1QV8vF5EeA%3D
> rved=0
>

Peter Wallace
Mesa Electronics


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Re: [Emc-users] Mesa Card Stepgens?

[Peter Wallace]

On Mon, 15 Apr 2024, Todd Zuercher via Emc-users wrote:


Date: Mon, 15 Apr 2024 19:27:19 +
From: Todd Zuercher via Emc-users 
To: "Enhanced Machine Controller (EMC)" 
Cc: Todd Zuercher 
Subject: [Emc-users] Mesa Card Stepgens?

I was working on this machine where I need a whole bunch of extra stepgens.  I 
am using a Mesa 7i85S and a 7i88 connected to a 5i25 card.  I was testing some 
of the stepper drives and I noticed that with one of the drive/motor 
combinations I am needing to use slightly longer step timing and lower max 
velocity.  I thought that this was odd, because all of the drives, motors, and 
mechanicals are the same for all of the ones I was testing.  The only 
difference is that the slower one was connected to a stepgen on the 7i85S and 
all of the others are on the 7i88.  So just for curiosity sake I checked the 
voltage at the input terminals of step/dir signals of the drive.  On the 
terminals connected to the 7i88 I found +/-5v, and on the one connected to the 
7i85S there is only +/-3v.  This is the only difference I've been able to find 
between the different joints in question.

Does it make sense that the voltages would be different on the step/dir outputs 
between the 7i85s and the 7i88?  Does it make sense that the difference would 
cause a difference in the required step timing?  Why might there be a 
difference between the output voltage on the two cards?

Both cards are getting their 5v from the 5i25.  The 7i85S is also connected to 
3 step/gen servo drives and their encoder's feedbacks.  Is it possible that the 
5v drain from the encoders might be causing the lower voltage on the 7i85S's 
outputs?



I would check the 5V rail at the 7I85S card, and if its low, power the 7I85S 
directly from 5V rather the through the parallel cable. ALso the very first 
lot (many years ago) of 7I85S cards were built with DS34C87 drivers which do 
not have full 5V drive. If you have this card, you can get 5V drive by using 
single ended sinking outputs and 5V+ to drive step+ and 7i85s step- to drive 
step-




Todd Zuercher
P. Graham Dunn Inc.<http://www.pgrahamdunn.com/index.php>
630 Henry Street
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031


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Peter Wallace
Mesa Electronics


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[Emc-users] Mesa Card Stepgens?

[Todd Zuercher via Emc-users]

I was working on this machine where I need a whole bunch of extra stepgens.  I 
am using a Mesa 7i85S and a 7i88 connected to a 5i25 card.  I was testing some 
of the stepper drives and I noticed that with one of the drive/motor 
combinations I am needing to use slightly longer step timing and lower max 
velocity.  I thought that this was odd, because all of the drives, motors, and 
mechanicals are the same for all of the ones I was testing.  The only 
difference is that the slower one was connected to a stepgen on the 7i85S and 
all of the others are on the 7i88.  So just for curiosity sake I checked the 
voltage at the input terminals of step/dir signals of the drive.  On the 
terminals connected to the 7i88 I found +/-5v, and on the one connected to the 
7i85S there is only +/-3v.  This is the only difference I've been able to find 
between the different joints in question.

Does it make sense that the voltages would be different on the step/dir outputs 
between the 7i85s and the 7i88?  Does it make sense that the difference would 
cause a difference in the required step timing?  Why might there be a 
difference between the output voltage on the two cards?

Both cards are getting their 5v from the 5i25.  The 7i85S is also connected to 
3 step/gen servo drives and their encoder's feedbacks.  Is it possible that the 
5v drain from the encoders might be causing the lower voltage on the 7i85S's 
outputs?

Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031


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