***DMM TECHNOLOGIES DYN4 USERS PLEASE READ***

[martyscncgarage]

1: DO NOT CONNECT THE DYN4 ENCODER OUTPUT SIGNALS TO ACORN INPUTS VIA THE RESISTOR METHOD TO ACORN INPUTS
The method may eventually damage the encoder.

2: If you are using an ACORN 3, the ALARM (drive fault signal) from the DYN4 is a pulsed signal. It is NOT high it is NOT low, and will not trigger the ACORN 3 input.

3: Connecting the DYN4 power (RS and L1 & L2) to per DMM's manual using the relay to power it up via Acorn and its Estop circuit will make it loose position everytime you hit Estop as you power down the DYN4 completely this way. I thought you could only power down the motor circuit (R&S) and leave the Logic circuit (L1 & L2) powered up, which you could BUT on power up first start of Acorn, the motor will lurch/twich about a 1/4 turn. This may or may not be a bad thing depending on the application.


DMM Technologies is looking at this
Centroid is also validating the input signal on Acorn 3 but by design, the inputs respond to steady HIGH or steady LOW signals
I am also going to some more testing tomorrow on #1 and #2
Marty

[Reedfirst]

Hey Marty,

Regarding number 1.

I have it working with an N channel (logic level) MOSFET. I wasn't convinced the resistor method was the safest way to do this. I have a few different N Channel MOSFETS arriving arriving tomorrow to test out. I'll let you know what I find out. But so far with the ones I salvaged out of an old PC power supply seem to be working great. They are just a bit over sized.

[mikes]

If it is a pulse signal or edge triger you are trying to capture, then you may want to use a latch for your logic. Of course the Acorn could sense this if it were programed to support edge triggering as an option.

[martyscncgarage]

Hey Marty,

Regarding number 1.

I have it working with an N channel (logic level) MOSFET. I wasn't convinced the resistor method was the safest way to do this. I have a few different N Channel MOSFETS arriving arriving tomorrow to test out. I'll let you know what I find out. But so far with the ones I salvaged out of an old PC power supply seem to be working great. They are just a bit over sized.

Yes, using an OPTO or other means of isolation is the right way.
The idea I have in mind at this point is to go through the DB25 as its inputs stand at 5VDC. Waiting for concurrence from DMM before proceeding.

I haven't caused harm to my encoder...yet, but didn't want folks taking a chance. I will pass on the offical word from DMM as soon as I get it. Likely today.

Marty

[martyscncgarage]

If it is a pulse signal or edge triger you are trying to capture, then you may want to use a latch for your logic. Of course the Acorn could sense this if it were programed to support edge triggering as an option.

Acorn 2 works. Acorn 3 does not.
I have encouraged DMM to make the alarm output user configurable, but not holding my breathe.
Yes, you could latch the pulse, but that adds a level of complexity. Don't want to go there if possible. I try to work on the K.I.S.S. principle
Going to test going in via the DB25 today if I have time

Thanks!
Marty

[spindle Nerd]

Acorn 2 works. Acorn 3 does not.
I have encouraged DMM to make the alarm output user configurable, but not holding my breathe.
Yes, you could latch the pulse, but that adds a level of complexity. Don't want to go there if possible. I try to work on the K.I.S.S. principle
Going to test going in via the DB25 today if I have time

Thanks!
Marty
Re: ***DMM TECHNOLOGIES DYN4 USERS PLEASE READ***Quote martyscncgarage

How to determine what model of Acorn you have? and this is really starting to get weird with all this DMM tech stuff.

[martyscncgarage]

If you have the removable terminal blocks that's a 3. It was released the end of December. Prior was a 2.

[Reedfirst]

OK, I did some tests and ended up using a very common and cheap BS170 N channel Enhancement MOSFET. It is T0-92 so it is quite small.

The MOSFET has three pins

Pin 1 DRAIN
Pin 2 GATE
Pin 3 Source

I made the connections as follows:

Pin 1 the "drain"of the Mosfet connects to the corresponding input you want to control on the Acorn.

Pin 2 the "gate" of the MOSFET to the DYN4 Drive's Db9 connector jp5 pin # 4

Pin 3 the "source" I soldered to the metal shell of the db9-connector.

The MOSFET fits inside a standard DB-9 Backshell and only one wire is needed to the acorn board.

I currently have this set up on all three of my Dyn4 Drives and they are working very well.

[ScotY]

If you have the removable terminal blocks that's a 3. It was released the end of December. Prior was a 2.

Are there differences between the two versions aside from the connectors and relays?

[martyscncgarage]

If you have the removable terminal blocks that's a 3. It was released the end of December. Prior was a 2.

Are there differences between the two versions aside from the connectors and relays?

DB25 pins are programmable. That was the main feature introduced in Acorn 3. Otherwise they are the same.