TTL Output Control

[testyourdesign]

• @clover I just bought a brand new Masso controller and I have a new relay module that has a 12V to 5v converter built in. All the relays are 5V. I believe it is the same one as Joe Manita used on his cnc router. You Can you please take a look and advise if this will work with MASSO TTL outputs and show me how you would wire it up and more importantly how to test it before connecting it to MASSO?
  

Thanks, Stephen Brown

 

[clover]

@testyourdesign - Nice board. From what I can see it looks pretty straight-forward . I cannot see if it's an active high or active low from the picture. Not that that is important. It looks like it might be designed for a maximum of 5 or 6 Volt triggering voltage. Looks fine for Masso's TTL outputs.

Simple to test:

1. Just wire the 12V to the blue terminal block Pos. to the right and Neg. to the left
   
2. Connect a wire from the 5V Pin on the multi-pin block to any one of the other pins marked 1 - 15. Pins 2 - 16 are opposite.
   
3. If the relay board is active high you should hear each relay click as you connect each pin.
   

See how that goes Stephen

 

[testyourdesign]

I bought it of of Ebay Could you determine a test procedure so we can test it to make sure it's compatible with Masso TTL? I think others could benefit from this information as the documentation is vague or missing or misleading on all these boards. BTW the photo on the ebay page shows 12V relays but the one they provided definitely uses 5v relays.

Unfortunately, I don't think the test you described above will be sufficient to make sure the board is properly isolated and ensure that it will not cause damage to the Masso TTL outputs.

Thanks, Stephen Brown

 

[masso-support]

@testyourdesign please wire the relay board through the optocouplers on the spindle connector this time, just in case if some voltage is not good then it will only burn the opto on MASSO. So please DO NOT use pin 2 & 3 on the MASSO Spindle connector.

Pin 4 and 5 is a transistor output for CW signal.

Pin 6 and 7 is a transistor output for CCW signal.

 

[testyourdesign]

Thanks for your feedback @masso-support but I feel that your response is simply not adequate. By simply directing us to use the spindle transistor output does not change the instructions you provided for TTL connections and it does not provide suitable replacement instructions for connecting a relay module. I think the Masso documentation needs to be changed and a new method needs to be defined specifying how to verify that the relay module will be suitable to work with your controller. If spindle pins 2 & 3 are not to be used then you need to say that in your documentation. We have 18 TTL outputs that could cause damage to the controller with the instructions that were provided. I think that this post will provide valuable information for other users and prevent significant problems if we do this properly.

Sincerely, Stephen Brown

 

[testyourdesign]

Quote from clover on December 18, 2018, 7:18 pm

@testyourdesign - Nice board. From what I can see it looks pretty straight-forward . I cannot see if it's an active high or active low from the picture. Not that that is important. It looks like it might be designed for a maximum of 5 or 6 Volt triggering voltage. Looks fine for Masso's TTL outputs.

Simple to test:

1. Just wire the 12V to the blue terminal block Pos. to the right and Neg. to the left
   
2. Connect a wire from the 5V Pin on the multi-pin block to any one of the other pins marked 1 - 15. Pins 2 - 16 are opposite.
   
3. If the relay board is active high you should hear each relay click as you connect each pin.
   

See how that goes Stephen

Hi @clover

I ran the simple tests as you requested. Connecting the 5v pin to pins 1-15 or 2-16 did nothing. Should I test the GND pin the same way? Should I measure the voltages on those pins?

Thanks, Stephen Brown

 

[clover]

Edit - See post below -

Ok Stephen. Since I have not yet been able to work out the circuit, we are experimenting.

So try this: add a wire between the Gnd Pin (that's the one closest the Blue connector) and the 12V Neg terminal.

And test again.

Meanwhile I try and find additional information.

Just to confirm - you want to connect these relays to the TTL outputs, is that correct?

 

[clover]

@testyourdesign

I have had a chance to check further and I do not believe the test described in the previous post will work. But I think the following may be Ok:

1. Just wire the 12V to the blue terminal block Pos. to the right and Neg. to the left
   
2. Connect a wire from the Gnd Pin (that's the one closest the Blue connector) on the multi-pin block to any one of the other pins marked 1 - 15. Pins 2 - 16 are opposite.
   
3. Hopefully these will cause the relays to click.
   

If the relays operate you have an Active Low Relay Board. Stephen let's know how you go.

Sorry I missed your earlier post, yes this is testing the input pins to Gnd instead of +5V. Patrick

 

[testyourdesign]

@clover

Confirmed... The negative pin does activate the relays one by one as I touch the individual pins.

The intent is to develop instructions on how to test a common relay module before connecting it to the Masso TTL outputs. I want to confident that my choice works before connecting it to any of the TTL output pins.

Thanks, Stephen Brown

 

[clover]

@testyourdesign

Does this solve your problem at this stage Stephen, or do you need a diagram?

 

[masso-support]

Quote from testyourdesign on December 18, 2018, 11:56 pm

Thanks for your feedback @masso-support but I feel that your response is simply not adequate. By simply directing us to use the spindle transistor output does not change the instructions you provided for TTL connections and it does not provide suitable replacement instructions for connecting a relay module. I think the Masso documentation needs to be changed and a new method needs to be defined specifying how to verify that the relay module will be suitable to work with your controller. If spindle pins 2 & 3 are not to be used then you need to say that in your documentation. We have 18 TTL outputs that could cause damage to the controller with the instructions that were provided. I think that this post will provide valuable information for other users and prevent significant problems if we do this properly.

Sincerely, Stephen Brown

The issue here is that if we can define that all the relay boards are same then yes we can have set of instructions but as there are so many no brand relay boards out there that we have to rely on general instructions from our side.

One of the things you can do is to measure the voltage between the negative of the relay board and the input signal that you plan to connect to MASSO, this way we will know if your relay board has floating voltage on the input which might cause issues.

 

[masso-support]

Quote from testyourdesign on December 19, 2018, 12:50 pm

@clover

Confirmed... The negative pin does activate the relays one by one as I touch the individual pins.

The intent is to develop instructions on how to test a common relay module before connecting it to the Masso TTL outputs. I want to confident that my choice works before connecting it to any of the TTL output pins.

Thanks, Stephen Brown

so for this relay board do you have some documentation of schematic from the manufacturer?

 

[testyourdesign]

@clover

Your test method determined that the relay module is active low. I understand this to mean that pins 1 though 16 on the multi pin block are active when connected to the ground pin on the multi pin block. So I need something to make the contact between those points in order for it to work. At this point I have a basic understanding on how to make the relay module work but I think we are still missing something before we can make the wiring diagram.

@masso-support

I measured the 5 volts between pins 1 through 16 and the ground pin on the multi pin block. I also found continuity between the ground pin on the multi block and the ground pin on the input connector. This is another typical relay module that does not come with documentation. Here is the link to the ebay page but I found a nearly identical one on Banggood which shows the pinout.

If I understand the Masso design correctly the TTL outputs pins send either a LOW signal or a HIGH signal through the Masso output pins 1-16 and spindle pins 2 and 3. This output signal needs to find the same ground as the Masso power in order for the output to be considered ACTIVE.

Does this mean we still need some other type of isolation board to separate the output from the relay module control pin?

What voltage ranges does Masso use for the LOW and HIGH output signals?

Thanks for all your help.

Cheers, Stephen Brown

 

[clover]

@testyourdesign

It seems that two of us are trying to stir the pot at the same time (@masso-support and myself). I hope that the attached drawing will help.

Note that you may use your relay directly connected between both the TTL pins and the Relay Pins without additional components. Just remember as you noted earlier that the Relays will close when the output pin on Masso goes to low (or close to 0V).

Also as @masso-support has noted it would impossible to draw a standard test procedure for relay modules because there are so many variations. I think the best we can do is to build up a library of test and connection procedures for individual boards as we come across them. I would expect that a photo of different modules would form part of this collection. One would then look to match a relay with the an image for the relay module's information. I realise that this is probably beyond support's time limitations so if @masso-support has no objections I might start with this relay module.

@masso-support I will draw-up and post a simplified circuit diagram of the Relay Module for reference purposes.

Hope this helps, Patrick

 

[testyourdesign]

@clover

Consedering that we are still experimenting, we should note a few important items to consider before wiring the relay module to the Masso.

• Masso TTL output is designed for 0V to 5V operation so relay module control circuit shouldn't exceed that range.
  
• Masso TTL ouput is set normally LOW until commanded to change but this can be inverted to HIGH thru F1 screen in case the Relay Module is active LOW like mine.
  

I also found some information on the data sheet for the chip that Masso uses indicating electrical limits for the Masso TTL outputs:

• Maximum capacity of -0.5 to +6.5 volts DC.
  
• Maximum rating of 50ma.
  

Can those values be the limits which cannot be exceeded? If so then should we specify that the relay module be tested to ensure the relay module doesn't cause problems.

Thanks, Stephen Brown

 

[clover]

@testyourdesign

Consedering that we are still experimenting, we should note a few important items to consider before wiring the relay module to the Masso.

Yes Stephen I have checked all the relay parameters and it is completely compatible with Masso.

Can those values be the limits which cannot be exceeded?

Yes, these are absolute limits that cannot be exceeded without risk to the component.

Just out of interest, the current required from Masso by your relay board is just 4mA i.e. less than 10% of absolute maximum of the HC14 part).

Although your relay board is advertised for switching 110-220vAC I would be a little concerned about switching these voltages. The +5V rail on the board is too close to the switching contacts for my liking. Other boards overcome this problem by allowing an air gap between the high voltage switching contacts and the low voltage required to operate the relays. See attached photo that shows an image of your board (or at least the image from the website where you purchased the board) at the left and an image of another similar board where an air gap is machined in on the right. That board is advertised here.

For a board without an air gap I wouldn't like to switch more than about 50-60V but, maybe I'm just playing it too safe! Patrick

 

[testyourdesign]

@clover,

Thanks for all the great information. I really only want the ability to operate a few 24V DC solenoids and switch simple functions on my spindle servo drive so the high voltage concern is not an issue for me but I am glad you mentioned it. These TTL controls expose the internal circuits of the Masso control to all kinds of outside influences without the benefit of optocouplers isolating the circuits so its really important for everyone attempting anything like this to do a thorough evaluation of the relay modules and everything else that is connected to the Masso before endeavoring on this path.

Do you foresee any potential issues or concerns if someone uses the same 12V DC power supply from the Masso controller to power the relay module or should we consider running it on a completely separate power supply?

Do you foresee any potential problem with ground loops or interference between the relay board and other masso outputs like relays or tower lights on Masso's the relay control pins?

I really appreciate the fact that you are taking your time to go through all these details with me. Hopefully paying it forward will be rewarding to you as well.

Cheers, Stephen Brown

 

[clover]

(@testyourdesign

Do you foresee any potential issues or concerns if someone uses the same 12V DC power supply from the Masso controller to power the relay module or should we consider running it on a completely separate power supply?

There would be no problems operating for the same power supply that runs the Masso provided of course it has enough grunt to run both. Another power supply is un-necessary.

Do you foresee any potential problem with ground loops or interference between the relay board and other masso outputs like relays or tower lights on Masso's the relay control pins?

No problems here either. Ideally, all earths (Negatives) should be wired to the same point, I have done this and the attached drawing shows the way I have wired my Masso CNC. It's called STAR wiring - all common negatives are wired to the same point, namely the power supply negative. The positive side is not as important but for symmetry I have star wired this also. I am an electronics guy and my setup is a little more elaborate than this diagram shows but it will give you the idea of how it is done.

I really appreciate the fact that you are taking your time to go through all these details with me.

It's my pleasure.

 

[testyourdesign]

@clover

Now that we have established the basic operating limits of the Masso Controllers TTL outputs I would like to discuss a significant problem I found in the Masso documentation. If you review the instructions on the TTL Output page you will notice that they show a 24V power supply connected to a Single Hi/Lo Adjustable Relay Module with the Masso TTL output connected to the input pin on the relay module. In my experience if you follow their instruction you will damage your Masso controller.

Here is what I discovered by testing their design...

The electrical circuit for the relay in their wiring diagram operates on the same voltage that is applied to the relay module which in this case would be 24V DC. The relay module does not have a voltage converter so the input pins on that relay module need 24V input to work properly. The HIGH level trigger jumper setting on that relay module simply means it needs a connection to +24V to trigger the relay. Where as the LOW level trigger jumper setting on that relay make it work when the input pin is connected to the -24V.

I believe that this instruction will damage the Masso controller since the TTL Output Pins 1 through 16 and Spindle CW/CCW pins 2 and 3 are limited to an absolute maximum of 6.5 volts. I think that Masso needs to correct this page and more clearly define the limitations of those output pins.

Could you please review my findings and let me know your thoughts?

Thanks, Stephen Brown

 

[clover]

@testyourdesign

I believe that this instruction will damage the Masso controller

Your post requires a more detailed response than just a few quick lines here on a Saturday evening. Your assumption is not valid and I will endeavour to explain why in more detail in the next day or so when time permits. Stephen I hope this is OK. Patrick