Dyn4 to Acorn cable - Why not utilize the Dyn4’s internal 5v power supply ?

[cut2cut]

Wouldn’t the Acorn to Dyn4 cabling be simplified if we utilized the Dyn4’s built in 5v power supply. It negates the need for an external 5vdc power supply ( or 24vdc with 2k ohm resistors ). Is there a technical reason why the dyn4’s internal 5v power supply isn’t utilized ?
The DYN4 manual shows on pages 17 and 35 that it’s internal 5v supply (on pin 24 of the JP4 connector) is available to use with open collector Dir and Pulse signals like what the Acorn provides on it’s screw terminals.  So I am confused as to why utilizing the 24 supply, which necessitates extra external resistors, would be desirable. The DMM flying lead cable has a 2k resistor. I'm informed that a single current limiting resistor on 24v will lead to the Dir and Pulse signals influencing each other.  A separate resistor to each, both coming from 24v would have been more appropriate and eliminated the cross-influence.
Can anyone suggest why we aren't utilizing the DYN4's built in 5v power supply in the Acorn to Dyn4 cabling ?

please see the attachments taken from the DYN4 manual :

Jake

[mick41zxr]

Cannot answer that question directly, however I believe DMM now make a header cable for Acorn that steps the 24v from Acorn down to 5v with a resistor.
Regards,
Michael

[Commotion]

I’m not familiar with DMM but I did use leadshine ac drives which has a similar 5v output. I originally wired it up using this 5v as signal supply but the servo would only rotate one way and would not rotate very fast. Not enough current to supply both a step and direction signal.

The 5v output is a very low amp supply 50mA or something and most likely just used to power the encoder on the servo motor.

I’m only guessing that DMM would be the same thing.

[martyscncgarage]

Why not use the cables that DMM makes to connect to Acorn?
FOLLOW THE SCHEMATICS provided by either Centroid or DMM is my suggestion.

Anything else is at your risk....

Marty

[cut2cut]

Why not use the cables that DMM makes to connect to Acorn?
FOLLOW THE SCHEMATICS provided by either Centroid or DMM is my suggestion.

Anything else is at your risk....

Marty

Is the DMM schematic posted anywhere ?

I need a longer cable so I need to make my own. Also, the DMM flying lead cable does not have a brake ( pin 19 ) lead, so even if it was long enough, I'd have to make my own cable. Believe me, I'd rather not have to make a cable but that's the reality of it.

Thanks,

Jake

[slodat]

Jake,

On DMM's web storefront I found this:

I wanted a bit more length and DMM said they were only offered in the 1m length.

I found this schematic on DMM's website.

[cut2cut]

Jake,

On DMM's web storefront I found this:


20180817_1517291_resized_s_large.jpg


I wanted a bit more length and DMM said they were only offered in the 1m length.

I found this schematic on DMM's website.

Thanks. Yeah, I have that one diagram. Its almost sufficient in that it shows the basic wiring but its not complete. It shows "input 5". I can assume it means "alarm" from a process of elimination. In one of Marty's videos he flashes a wiring diagram on a piece of paper. Thats what I'm looking for but its nowhere easily accessible on DMM's website from what I can tell. I'll email DMM directly and hope someone is working on a Sunday.

Jake

[slodat]

Jake- this schematic shows input 5.

[cut2cut]

Jake- this schematic shows input 5.

Thanks.. however associating that diagram with the other one is a bit confusing should someone come to this thread looking for answers. It would be best if DMM just adds detail to the simple diagram by adding Alarm : Alarm/input 5. Then that wiring diagram can "stand on its own two feet", so to speak. The second diagram that you referenced ( that shows the alarm reference ) is meant for a wiring option using a 5vdc power supply, so people that have that DMM flying lead cable may try to use a 5v power supply. Since the cable already has 2k ohm resistors in it the 5v power supply wiring method won't work. You might think its over thinking on my part, but people have made the mistake by using the 5v power supply wiring method/option with the DMM flying lead cable.

Anyway, I've relayed the idea to DMM as they replied this morning by sending me the simple cable diagram. I'm hopeful they'll make the alteration to the diagram to include " alarm " and all will be well in the universe

Jake

[cut2cut]

here is an "unofficial" edit to the diagram. I simply added the "DriveOK/alm" [alarm] designation :

Jake