pliptm Posted September 5, 2016 Report Posted September 5, 2016 Hi! I figured I may have run into trouble here and thought to ask for your opinion. I got my hands on Bautz DSK-12 AC motor driver and Unitronics Samba (4.3 inch, transistor type) PLC and acquaintance of mine asked me to do some programming. Firstly, I discovered that encoder (what I have to use) is running on 5v (actually to get encoder values from driver I have to feed it 5v and not any higher). Thought that I could buy fast (50kHz) optocoupler to ramp up 5v to 24v and feed it into PLC. Secondly, I discovered that this type of motor driver takes +/-10v to change motor direction and velocity. (ex. there is 2 pins, first pin has to have ZERO aka reference voltage and other pin has to have zero to +10v OR zero to -10v, accordingly which direction user wants to motor go). I do not have any thought how to fix this one. Do I have to order some kind of additional position controller or is there something else what can I do? Bautz DSK12 datasheet: http://www.ahs-antriebstechnik.de/pdf-dateien-e/Servo Drives Servo Amplifier/Manual DSK12-gb.PDF (German version, for german friends out there: http://www.servodyntechnik.de/DSK_12_d.PDF) Help from you guys would be greatly appreciated. Greetings, Steven
Kikis Posted September 6, 2016 Report Posted September 6, 2016 Hello Steven, For the encoder connection you can use a product like the one shown in the link below, it converts 5V high speed pulse to 24V. https://www.aliexpress.com/store/product/4-channel-5V-to-24V-grating-PLC-pulse-converter-high-speed-conversion-IO-opto-isolated-interface/908764_32282655234.html Regarding analog output for speed and direction control, Samba TA22 outputs unipolar 0-10v, not bipolar as your application requires. Since Samba supports Modbus communication protocol, you could use a Modbus module featuring bipolar analog output like ADAM-4024. Btw if Samba's 4.3 inch touch screen is not essential for your project, you can use Jazz JZ10-J-UA24 PLC unit. It features 5khz high speed input and +/-10V analog output.
pliptm Posted September 7, 2016 Author Report Posted September 7, 2016 On 9/6/2016 at 6:26 PM, Kikis said: Hello Steven, For the encoder connection you can use a product like the one shown in the link below, it converts 5V high speed pulse to 24V. https://www.aliexpress.com/store/product/4-channel-5V-to-24V-grating-PLC-pulse-converter-high-speed-conversion-IO-opto-isolated-interface/908764_32282655234.html Regarding analog output for speed and direction control, Samba TA22 outputs unipolar 0-10v, not bipolar as your application requires. Since Samba supports Modbus communication protocol, you could use a Modbus module featuring bipolar analog output like ADAM-4024. Btw if Samba's 4.3 inch touch screen is not essential for your project, you can use Jazz JZ10-J-UA24 PLC unit. It features 5khz high speed input and +/-10V analog output. Hello! Thank you for your reply. I will look into those methods you supplied. Meanwhile, could you or anybody possibly give advice, what AC motor driver would be good (and maybe common in europe) with what I would not need any additional devices to control it with Samba. Thing with samba is that we already have this on ordered and at my hand (SM43-J-T20). Steven
Kikis Posted September 8, 2016 Report Posted September 8, 2016 Hello Steven, Your Samba model has no analog output. Also max switching frequency of transistor outputs is 500Hz which is too low to control a servo drive via pulse & direction. I think the only choice you have with SM43-J-T20 is to use a communication protocol like Modbus and select a drive which supports this protocol.
MVP 2023 Joe Tauser Posted September 8, 2016 MVP 2023 Report Posted September 8, 2016 This looks like an old-school velocity control via input signals servo drive. I didn't see any communication options in the manual, so talking to the drive via serial connection is out. You didn't give the full part number so we don't know if it has the -T pulse control option. You didn't describe what you're trying to do - is forward and reverse required? Do you need precision in rotational position, or is speed control more important? If you're limited to controlling it with a +/- 10V signal for velocity, you've got the wrong Samba model. See if you can exchange it for a -TA22, and then get yourself an external analog converter module that converts 0-10V to +/- 10V. They are available. Let us know. Joe T. PS - @ Kikis - the 500 Hz spec bothered me so much I got an SM43-J-T20 out of stock and put a scope on it. The sourcing output is like the old V120; it will go to 1 KHz with no problem and turns into a triangle wave above 1.5 kHz. The interesting thing is if you run it into a PNP to NPN converter you can get as much as 5 kHz without a problem, as the transistor switches at a low voltage without regard to the input waveform, producing a nice clean output squarewave. This is an un-authorized spec, of course.
Kikis Posted September 8, 2016 Report Posted September 8, 2016 Hello Joe, Thanks for sharing your test results with us, they are very valuable. I usually use Delta ASDA A2 servo packages (motor & drive) for positioning control where the encoder resolution is 1,280,000 pulses/rev. So even 5KHz output is too low to control this servo drive via pulse train. It could be done by adjusting the electronic gear ratio on the drive but then it will significantly decrease positioning accuracy. Therefore when it comes to servo positioning control via step & direction, i use a V130 or V350 model with 200KHz output and PTO commands within Visilogic. In general, i think it's better to "talk" to the drive by a communication protocol, so that you let servo controller to precisely control the motor in full closed loop. PTO is an open loop way of control which may not be sufficient if there are very high accuracy positioning requirements.
pliptm Posted September 8, 2016 Author Report Posted September 8, 2016 3 hours ago, Joe Tauser said: This looks like an old-school velocity control via input signals servo drive. I didn't see any communication options in the manual, so talking to the drive via serial connection is out. You didn't give the full part number so we don't know if it has the -T pulse control option. You didn't describe what you're trying to do - is forward and reverse required? Do you need precision in rotational position, or is speed control more important? If you're limited to controlling it with a +/- 10V signal for velocity, you've got the wrong Samba model. See if you can exchange it for a -TA22, and then get yourself an external analog converter module that converts 0-10V to +/- 10V. They are available. Let us know. Joe T. PS - @ Kikis - the 500 Hz spec bothered me so much I got an SM43-J-T20 out of stock and put a scope on it. The sourcing output is like the old V120; it will go to 1 KHz with no problem and turns into a triangle wave above 1.5 kHz. The interesting thing is if you run it into a PNP to NPN converter you can get as much as 5 kHz without a problem, as the transistor switches at a low voltage without regard to the input waveform, producing a nice clean output squarewave. This is an un-authorized spec, of course. I indeed forgot to describe. Yes, both forward and reverse motion is required for motor. Basically motor is connected to slider, at power up, slider moves to home position (determined by limit switch) and then goes to end limit switch (this way PLC could calculate total length of slider track and/or if it has been changed). Then part is pushed in front of slider and slider steadily starts to move towards home switch, when home switch registers touch, this meant that slider is touching the end of the part and home is touching the start of the part. This way PLC could calculate part length and starts work operation. Most important is to get encoder values right, because PLC is going to calculate part length according to encoder value. So speed control is not that important. Could I possibly order some extension modules for t20 to add analog outputs for +/- 10V? They do not exchange PLCs here, so only cheap way is to buy some kind of extension modules. My thought was that I will use IO-AI4-AO2 extension module and for encoder I will use fast optocoupler (50-100kHz) to ramp 5v to 24v. To add Eth port to Samba I would use V10017ET2 module and then EXA2X to create module port for IO-AI4-AO2. Is this legit way to do this or is there anything I could do to make things easier? This way I am approximately saving ~150 bucks, compared to buy samba t22 (and maybe still have to buy additional modules)? Motor drive full code: Bautz DSK 12 Samba full code: SM43-J-T20 Steven
Kikis Posted September 8, 2016 Report Posted September 8, 2016 4 hours ago, pliptm said: Could I possibly order some extension modules for t20 to add analog outputs for +/- 10V? They do not exchange PLCs here, so only cheap way is to buy some kind of extension modules. ..... To add Eth port to Samba I would use V10017ET2 module and then EXA2X to create module port for IO-AI4-AO2 Samba does not support local expansion I/O modules via EX-A2X. If you want to expand the PLC, you have to add CANbus card and use the remote adapter EX-RC1. However this will significantly increase the total cost in the range of a small PLC from the enhanced Vision series. It will also add complexity to your project as EX-RC1 requires extra programming. If i was in your Position, i would have left the Samba for a future project and go for a V350. Could you give us the exact part number of your drive? If your drive supports pulse and direction input (indicated by-T on the drive's part code), you could use V350 TR6 model and control the motor with PTO commands. This way you also don't need to connect the encoder input. 1
MVP 2023 Joe Tauser Posted September 8, 2016 MVP 2023 Report Posted September 8, 2016 Steven- I'm sorry you can't exchange the controller. The Samba, like the Jazz, is a limited-function product that unfortunately sometimes gets purchased before all the variables are known because the price is so attractive. Then you hit The Wall, as in your case. I've done it more than once myself. There's really no alternative other than to learn from your mistake and use a different controller- you'll literally spend hours trying to make something work that doesn't fit, and eventually you have to look at the value of your time. Older/cheaper servo controls drive me crazy for this exact reason. Anytime I get involved with a servo I use something that has a serial port. It's actually quite easy to use the Protocol block to generate the couple of commands needed to make the servo do whatever you want. The manufacturer's setup software does the heavy lifting of initial configuration, and from an application standpoint you just have to feed it velocity, position, and run commands via serial strings. Joe T.
pliptm Posted September 8, 2016 Author Report Posted September 8, 2016 1 hour ago, Kikis said: Samba does not support local expansion I/O modules via EX-A2X. If you want to expand the PLC, you have to add CANbus card and use the remote adapter EX-RC1. However this will significantly increase the total cost in the range of a small PLC from the enhanced Vision series. It will also add complexity to your project as EX-RC1 requires extra programming. If i was in your Position, i would have left the Samba for a future project and go for a V350. Could you give us the exact part number of your drive? If your drive supports pulse and direction input (indicated by-T on the drive's part code), you could use V350 TR6 model and control the motor with PTO commands. This way you also don't need to connect the encoder input. Yeah, sorry, thought that I forgotsomething. Exact part number for my drive would be DSK12-C8-000-AA. So no extra user modules attachted to driver.
pliptm Posted September 8, 2016 Author Report Posted September 8, 2016 8 minutes ago, Joe Tauser said: Steven- I'm sorry you can't exchange the controller. The Samba, like the Jazz, is a limited-function product that unfortunately sometimes gets purchased before all the variables are known because the price is so attractive. Then you hit The Wall, as in your case. I've done it more than once myself. There's really no alternative other than to learn from your mistake and use a different controller- you'll literally spend hours trying to make something work that doesn't fit, and eventually you have to look at the value of your time. Older/cheaper servo controls drive me crazy for this exact reason. Anytime I get involved with a servo I use something that has a serial port. It's actually quite easy to use the Protocol block to generate the couple of commands needed to make the servo do whatever you want. The manufacturer's setup software does the heavy lifting of initial configuration, and from an application standpoint you just have to feed it velocity, position, and run commands via serial strings. Joe T. Could I get away if I just use another Drive unit (which has serial port) and use it with Samba? If I understand it correctly, then I would still need some additional module for samba, right? If so, could you name it, do I need rs232, rs485, canbus or eth module? Steven
MVP 2023 Joe Tauser Posted September 8, 2016 MVP 2023 Report Posted September 8, 2016 Yes, you can add a communication module to the Samba. The part number for the serial card is V100-17-RS4X. Joe T. 1
pliptm Posted September 8, 2016 Author Report Posted September 8, 2016 4 hours ago, Joe Tauser said: Yes, you can add a communication module to the Samba. The part number for the serial card is V100-17-RS4X. Joe T. Thanks for you help Joe and others! We decided to buy serial card for samba and order new driver kit (with motor and serial connection). 1
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