Kikis Posted March 7, 2013 Report Share Posted March 7, 2013 Hi guys, I'm thinking of buying the following 3-axis stepper motor kit from ebay. http://www.ebay.com/itm/US-Free-ship-3-axis-425oz-in-Nema23-stepper-motor-112mm-matched-driver-CNC-Kit-/251235147807?pt=LH_DefaultDomain_0&hash=item3a7ec8201f I will not use the breakout board included in the kit but i wil use a Unitronics V350-35-TR34 instead. My application requires simple, not very accurate positioning of 3 axes. My questions are the following: The driver accepts pulses of 5VDC while the PLC HSO is 24VDC. How can i convert the high frequency pulse to 5VDC? Also the Pulses are NPN type. Is this a problem for the driver? Thanks in advance Quote Link to comment Share on other sites More sharing options...
MVP 2014 Simon Posted March 7, 2013 MVP 2014 Report Share Posted March 7, 2013 My brief comments as follows: * the NPN outputs of the TR34 are an advantage when working with your 5V signal, as they will work with switching voltages as low as 3.5V (p4 of Spec Sheet) * you will need a 5VDC supply (for example a regulated plugpack (what Australians call them) or "Wall-Wart??" (what the Americans call them)) * The wiring details for the stepper driver are a bit vague, but looks like the step and direction are opto-isolated. Assuming this is the case, put 5V direct from the supply to the (+5) terminals of the inputs, then wire the (-) terminal of each input to the PLC outputs, then connect PLC common to 0V of your supply (and link with 0V of your 24VDC PLC supply). I hope this helps, and please note my assumptions. You may be able to get more detail direct from the stepper suppliers own website. Quote Link to comment Share on other sites More sharing options...
Kikis Posted March 8, 2013 Author Report Share Posted March 8, 2013 Simon, thanks for your great support. Your post was really helpful for me. Please let me ask another question... What happens if i want to use a Jazz model to move one motor? Operating voltage of JZ 10-11-PT15 HSO is 20-28.8VDC. Quote Link to comment Share on other sites More sharing options...
MVP 2014 Simon Posted March 11, 2013 MVP 2014 Report Share Posted March 11, 2013 I took a look at the installation guide for the JZ10-11-PT15. It's a bit of a grey area but I would suggest the following: * the above specification that you quote (20.0-28.8VDC - which is 24VDC +/- 10%) relates to the power supply requirements for the output supply terminals at the right-hand end of the output terminal strip. This is the power required to drive the relays, and is the reference for the PNP solid state output. * If you look at the wiring diagram for the NPN output, you can see that the above 24V supply is not referenced, and a separate "+Vnpn" supply is reference instead. This "+Vnpn" would be your auxiliary 5VDC, and also connect the 0V of the 5V supply to the 0V of your 24V supply.. The on-state voltage of the npn output is 0.4VDC, so it should work. * note the lower frequency of the Jazz output compared to the V350-35-TR34, of 32kHz in NPN mode, when driving a resistive load. As you can see there are a few maybes. If you want to be sure before purchasing the unit i would forward the question to your local supplier and/or to support@unitronics.com Quote Link to comment Share on other sites More sharing options...
Kikis Posted March 12, 2013 Author Report Share Posted March 12, 2013 Thanks again for the feedback. I was thinking of connecting a 2k/1w resistor in series with my PLC NPN output and connect it with the (-) pulse input terminal of the stepper drive. Then connect +24VDC directly to the (+) pulse terminal of the drive. The input is opto-isolated. Should it work this way or not? Quote Link to comment Share on other sites More sharing options...
MVP 2023 Joe Tauser Posted March 12, 2013 MVP 2023 Report Share Posted March 12, 2013 I have connected a stepper driver in exactly the way you describe and it works fine. Let's look at the design specifics- Your control specifies a 5V input pulse, which is extremely common. It has an internal resistor in series with the opto-coupler to limit the current to about 10 mA at 5V. As Simon mentioned, the on-state voltage drop of an NPN output is 0.4V, so we can effectively ignore it. The voltage the resistor will need to drop is 19V at 10 mA, resulting in a series resistor size of 1900 ohms, or the 2K you mention. The power rating of the resistor is 0.2W, so you really only need a 1/2W resistor. If you can locate a 2K resistor, great. A 2.2K is much easier to come by and will result in slightly lower current through the opto-isolator but it will still work. This is the value I use. Joe T. Quote Link to comment Share on other sites More sharing options...
Kikis Posted March 14, 2013 Author Report Share Posted March 14, 2013 Joe, I'ts good to know that you have successfully tried this in the past. I think that is the best solution to the problem... Thanks! Quote Link to comment Share on other sites More sharing options...
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