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  1. #1
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    Servo Drive Controls I/O

    Hi. Looking foe clarity on this. Will be used on a spindle.

    My servo drive has DB44 connection with 7 outputs and 8 inputs for faults and controls (aside from the 0-10v and communication port etc).
    These are shown in the manual connected via switches / relays / opto etc. Some will be direct connection to BOB.

    Question is: That is a lot of messy relays. A smaller optocoupler I/O module would do the job... Yes?
    Thinking along the lines of an opto for all the fault outputs connected out to a single SSR for E-stop?

    I'd prob only need 2 of the inputs (on/off & CW/CCW) so a couple of relays won't hurt too much.

    Cheers.
    Daz.

  2. #2
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    Re: Servo Drive Controls I/O

    Hi,
    post the manual of the driver so we can see how the manufacturer has arranged the IO.

    Most modern servo drives have opto-isolators on the inputs already. Most outputs are open collector transistors but they
    are photo-transisitors themselves.

    Craig

  3. #3
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    Re: Servo Drive Controls I/O

    Quote Originally Posted by joeavaerage View Post
    Hi,
    post the manual of the driver so we can see how the manufacturer has arranged the IO.

    Most modern servo drives have opto-isolators on the inputs already. Most outputs are open collector transistors but they
    are photo-transisitors themselves.

    Craig

    Here you go Craig.
    http://servo.xlichuan.com/Private/Pr...6713131150.pdf
    Has opto built in and shows I can use either opto or relay as fault triggers.
    Just trying to work out the neatest and most efficient way of hooking it up.
    The 8 chnl opo board I have lying around looks nice and compact, compared to ugly relays.

    Have it all set up on test bench (lounge floor) with relay boards atm ready for testing on spare pc.

    For inputs I'll prob only need 3, with peramiters of 0,1 & 7. ie: SRV_ON / ALM_CLR / CW_CCW. These can come direct from BOB.
    The other inputs I could prob disable. Yes?
    (Apart from the 0-10v / GND inputs of course)

    I'm actually all wired up to use 'enable' on my stepper drives which comes from pin 14 on my bob. Estop disables them, then re-enables them with mach reset.
    I'm thinking the servo ALM_CLR function can be taken from there to a timed relay that turns itself off after a few seconds when reset is hit.
    (unless you have a good alternative).

    Daz.

  4. #4
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    Re: Servo Drive Controls I/O

    Hi,
    on page 13 it shows that digital outputs DO0-DO4 are open collector but with the emitter of each transistor tied to the COM- of the drive.
    DO5 however is a floating opto-transistor.

    Neglecting DO5 for the moment if you have one wire dedicated to connect COM- of the drive to the GND or COM of your BoB then the digital outputs DO0-DO4
    just become plain active low 24V tolerant outputs of your drive and active low inputs to your BoB. Unless you need to switch a load or absolutely insist on galvanic isolation
    why bother with a relay?

    How are you planning on driving the step/direction or alternately the CW/CCW inputs? Page 12 shows 5V differential, which is the highest speed and preferred, or
    12-24V inputs with an EXTERNAL resistor, or on the top of page 13 12-24V with the BUILT-IN resistor.

    You absolutely MUST decide early on how you are going to signal these inputs and be ABSOLUTELY sure you have it right or you will blow the photodiode in the drive
    and wreck it.

    All modern AC servo drives have very similar input/output circuits. My Delta B2 series servos have an almost indentical input arrangement. Because I need to signal my servos at 416kHz
    I perforce used the differential signalling scheme. It is a twin wire +2.5/-2.5V signal and connects to the photodiode through the built-in 270 Ohm resistor only. If you make the mistake of trying to
    feed 24V down there WITHOUT the benefit of the 2.2 kOhm built-in resistor or one that you supply externally you will wreck it.

    this is my wiring scheme:
    2 wires Step signal (5V differential)
    2 wires Dir signal (5V differential)
    1 wire COM- of the drive to COM- of my BoB
    1 wire Servo Enable (output of BoB to opto-input SERVO-ON in the drive)
    1 wire Alarm reset (output of BoB to opto-input ALRMRESET in the drive)
    1 wire Alarm (ALARM output of the drive to a 24V tolerant input on my BoB)

    Note that I have only one alarm output from the drive. I will in future have at least two, one will be o'heat/o'current/o'voltage, per normal but the other
    will be FOLLOWING-ERROR. Having just one alarm simplifies matters when I'm still building but the alarm set-up will become more sophisticated in service.

    Craig

  5. #5
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    Re: Servo Drive Controls I/O

    On another note Craig.
    I've been dithering over a UC300ETH with 2x UCBB boards and switching to UCCNC.
    Had a brief read and as far as I can tell I can assign various different functions to the pins.

    So for example I could direct connect the servo fault outputs to some inputs on the UCBB and assign all their pins to the same 'Estopin' (function 91 I think).
    Thus eliminating the need for any relays / opto etc.
    Is this correct?

    If so.... I'm sold.

    Got some reading to do lol.

    Daz.

  6. #6
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    Re: Servo Drive Controls I/O

    Quote Originally Posted by dazp1976 View Post
    Here you go Craig.
    http://servo.xlichuan.com/Private/Pr...6713131150.pdf
    Has opto built in and shows I can use either opto or relay as fault triggers.
    Just trying to work out the neatest and most efficient way of hooking it up.
    The 8 chnl opo board I have lying around looks nice and compact, compared to ugly relays.

    Have it all set up on test bench (lounge floor) with relay boards atm ready for testing on spare pc.

    For inputs I'll prob only need 3, with peramiters of 0,1 & 7. ie: SRV_ON / ALM_CLR / CW_CCW. These can come direct from BOB.
    The other inputs I could prob disable. Yes?
    (Apart from the 0-10v / GND inputs of course)

    I'm actually all wired up to use 'enable' on my stepper drives which comes from pin 14 on my bob. Estop disables them, then re-enables them with mach reset.
    I'm thinking the servo ALM_CLR function can be taken from there to a timed relay that turns itself off after a few seconds when reset is hit.
    (unless you have a good alternative).

    Daz.
    You don't have to make this complicated you can use Step /Dir for this also for your spindle control
    Mactec54

  7. #7
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    Re: Servo Drive Controls I/O

    Hi,
    I don't know enough about UCCNC and the UC series of motion ccontrol boards to comment.

    I do know that ger21, a very widely respected CNCer and supporter of this forum swears by UCCNC and that is a good reccomendation.

    I use Mach4 and an ESS. I can assign inputs and outputs within the structure normally associated with paralell ports. For example I have
    set my ESS this way:

    Port1:
    pin 1output
    pins 2-9 outputs
    pins 10-13 inputs
    pin 14 output
    pin 15 input
    pins 16-17 outputs
    total:
    5 inputs
    12 outputs

    Port2
    pin1 output
    pins 2-9 inputs
    pins 10-13 inputs
    pin 14 output
    pin 15 input
    pins 16-17 outputs
    total
    4 outputs
    13 inputs

    Port3:
    pin1 ouput
    pins 2-9 inputs
    pins10-13 inputs
    pin14 output
    pin15 input
    pins16-117 outputs
    total:
    4 outputs
    13 inputs

    TOTAL (all three ports):
    20 outputs
    31 inputs

    You can see that I have elected to make my motion control board input dominant, but you have the flexibilty to choose to make it output dominant.

    Once you start selecting breakout boards they too constrain your flexibility, you are required to follow the input/output balance supplied
    by the manufacturer.

    For this reason I use MB2's by Homann Designs in Australia., not to be confused with the MB3 by CNCRoom of Malaysia. The reason I like
    them is because they are bi-directional, do not have any opto isolators nor relays and thus I retain the best possible flexibility with regard
    how I assign and use my IO. That does mean that if I want optos or relays or PWM filters I have to add them as I see fit. Given that electronics
    is my thing that represents no trouble to me. Note the MB2 is almost identical to the C10, which at $23.00 is a steal. I would recommend MB2's
    OR C10's if you are prepared to add a little circuitry as required.

    If you don't want to do any electronics then consider the MB3 by CNCRoom. Its made specifically for the ESS, which they also sell. Your are now required to follow the
    design principles of the MB3, but it is a well balanced design with respect to inputs and outputs. In particular it has 12 differential outputs which are the perfect match
    for your servo drive, and any other servos you have. It has one dedicated PWM output circuit and two relay output circuits. All in all a well balanced and quality design.

    I have been using Mach4 for six years with this combination and the combination has proven to be able to handle all that I throw at it, and all my imagination can
    conceive.

    Craig

  8. #8
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    Re: Servo Drive Controls I/O

    [QUOTE=joeavaerage;2446642]Hi,
    /QUOTE]

    Hi.

    If I was using the stp/dir inputs I'd be using 5v most definately.

    I was planning to run this in speed mode only to start with as par page 24 diagram. I didn't think I needed to use stp/dir unless I was hybrid?.
    Anyhoo the jist I got was.
    Pins 41,42- for rpm 0-10v / gnd
    DIO for servo on switch
    DI1 for alm clr relay
    DI5 for direction command (modified onto DI2, or not). CW / CCW controlled from bob to relay with NC = CW, NO = CCW (or vice versa).

    Then the DO 0-5 wherever they're going.


    Bitten off more than I can chew with a servo maybe!.

    Daz.

  9. #9
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    Re: Servo Drive Controls I/O

    Hi,
    you can run a servo as a free running motor in two ways.

    One way is to use velocity mode of the servo and control the speed with a 0-10VDC signal, which you can reverse by a DPDT relay.
    It seems that is your preferred method.

    You could also use Step/Direction, or its close analogues CW/CCW or quadrature. These methods require pulse signaling,
    and often at pulse speeds that mandate differential signaling. The advantage of this strategy is that you have position control of your spindle
    which may help with tool changing , spindle indexing and rigid tapping.

    I have a second hand 1.8kW Allen Bradley servo as a spindle motor and I use both methods.

    Most modern AC servos, which certainly includes my Allen Bradley (circa 2005) and my new Delta servos, have dual mode capability, and I believe
    if you read your manual you would find your servo capable of dual mode also.

    If you program the drive to be dual mode you would chose velocity/position mode. Which mode is active is determined by a single digital input to the
    drive from your BoB. In position mode you would signal Step/Dir (or one of its analogues) and in velocity mode your BoB would supply a 0-10VDC signal for speed.

    You can have Mach4 run a Step/Dir spindle as a free running motor, but it's not it's normal or native operation. Mach4 is natively a PWM output to control spindle
    speed. For this reason I set my spindle motor to be primarily PWM speed controlled but when I need to do some rigid tapping say, then I assert position
    mode and so my spindle becomes in effect a C axis. In practice I very seldom use the spindle as a C axis, and if I were starting from scratch I would not bother with
    it. Its not that its particularly hard to do but if this is your first foray into servos then setting simpler goals at the start are likely to result in a more satisfying experience.

    Both the Allen Bradley and Delta servos have very good manufacturer written set-up and tuning software that allow you to use a PC to program the firmware of
    the drive. I do not know if Lichuan servos have such software....but you really must get it if they have it. Programming a servo drive by pushing buttons on the drive
    like a microwave is very tedious and error prone. There are hundreds of tuning parameters...and most of them need not concern you....but some concern you greatly
    and you must use them to your best advantage. Tuning software really really helps.

    I suggest you consider these questions:
    1) Do I require position control of the spindle or just want it?
    2) If I want it, am I prepared for the extra complexity....or would I wait until I've got more
    'normal' operations in hand and then worry about position control?
    3) Position control requires pulse signaling, so would I go dual mode or would I stick to Step/Direction (or one of its analogues) and induce my
    control software to provide a free running Step signal?

    Craig

  10. #10
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    Re: Servo Drive Controls I/O

    Quote Originally Posted by joeavaerage View Post
    Hi,
    you can run a servo as a free running motor in two ways.

    One way is to use velocity mode of the servo and control the speed with a 0-10VDC signal, which you can reverse by a DPDT relay.
    It seems that is your preferred method.

    Both the Allen Bradley and Delta servos have very good manufacturer written set-up and tuning software that allow you to use a PC to program the firmware of
    the drive. I do not know if Lichuan servos have such software....but you really must get it if they have it. Programming a servo drive by pushing buttons on the drive
    like a microwave is very tedious and error prone. There are hundreds of tuning parameters...and most of them need not concern you....but some concern you greatly
    and you must use them to your best advantage. Tuning software really really helps.

    2) wait until I've got more
    'normal' operations in hand and then worry about position control?

    Craig
    Thanks Craig.
    Yes I'll keep it simple unless I need to venture out in years to come.
    So I guess I'm about right in my previous comment regarding wiring of velocity mode (speed mode in my case)?.

    I did purchase the serial RS485 - RJ45 data line and software set. On their way. I didn't fancy going through the buttons process.
    Mind you even then I need to remember to short between pins 33-34 by the look of it. Jeez.

    Sounds like I ccould control a few of these drives through the CN1/CN2 links, only shorting the last servo in the chain.
    That could be interesting

  11. #11
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    Re: Servo Drive Controls I/O

    Quote Originally Posted by joeavaerage View Post

    I suggest you consider these questions:
    1) Do I require position control of the spindle or just want it?
    2) If I want it, am I prepared for the extra complexity....or would I wait until I've got more
    'normal' operations in hand and then worry about position control?
    3) Position control requires pulse signaling, so would I go dual mode or would I stick to Step/Direction (or one of its analogues) and induce my
    control software to provide a free running Step signal?

    Craig
    So far.
    I've wired the drive up to the mains, breaker, filter, 4mm2 cable, connected the motor and the jog tests went good. So it works on it's own.

    I've wired all the I/0 to some 8 way relay modules for now (with onboard opto and hi/lo jumpers) 1 of 5v and 1 of 24v to a DB44 screw teminal block.
    Found a little rocker switch to use for servo on/off.
    Mach 3 test PC and 5 axis bob with onboard 0-10v.
    A 5v and 24v power supply.

    I think I've gone through the wiring a dozen times and still too scared to try it!

    In the meantime. I've ordered a new control box deep enought to fit it, and everything else into.
    And also ordered:
    A 72v psu for my Z.
    A larger 60v psu for my x,y, (to space save).
    And put in a quote for UC300eth, 2*UCBB boards, UCCNC lic, and a load of cabling.
    The 2 plain IDC26 (inputs) and ID16 (analogue) terminal blocks Ill get from aliexpress.

    Daz.

    Oh and. I think I can wire the error outputs directly to the UCBB inpts and program UCCNC shortcuts to either estop and/or feedhold options, so no need for messy relays and things then. Correct?.

    Daz.

  12. #12
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    Re: Servo Drive Controls I/O

    Quote Originally Posted by joeavaerage View Post
    Hi,
    you can run a servo as a free running motor in two ways.

    I suggest you consider these questions:
    1) Do I require position control of the spindle or just want it?
    2) If I want it, am I prepared for the extra complexity....or would I wait until I've got more
    'normal' operations in hand and then worry about position control?
    3) Position control requires pulse signaling, so would I go dual mode or would I stick to Step/Direction (or one of its analogues) and induce my
    control software to provide a free running Step signal?

    Craig
    Hi guys. Thanks for all the info.
    I've been doing a lot of instruction manual reading (not normally the man thing to do lol)

    So. For basics:
    1. I assumed step/direction control would lose me an axis, I don't, I'm a dumbass, nuff said.

    2. It's a 2500ppr encoder, quick calculations suggest at least 150khz needed so bye bye parport and hello UC300eth. I feel the 400eth is a bit port limited, especially if I end up with 5 axis and a tool changer (unlikely but I wish). I did look at the Pokeys57 but I wasn't convinced with support and being mach limited.

    3. Thinking of putting it in hybrid pos/spd mode and wiring it both ways step/dir on 5V, analogue 0-10v, DI/DO on 24v. I can then switch between the 2 depending on application or whichever is more accurate. YES?

    4. Will fit a small button control attached to machine enclosure for srv on/off and reset. Software will be in estop unless servo is enabled/on.

    5. UCCNC looks pretty good on paper. 300eth gives me the option of uccnc, mach 3 or mach 4.
    Am going to partition my PC into a triple boot using win7 (I hate 10!). Trial all 3 on their own partitions to avoid conflicts and go with the one I like.

    What's best for PC communication via LAN controller. Is the onboard fine or should I go with aa pci card?.

    Thanks.
    Daz.

  13. #13
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    Re: Servo Drive Controls I/O

    Quote Originally Posted by dazp1976 View Post
    Hi guys. Thanks for all the info.
    I've been doing a lot of instruction manual reading (not normally the man thing to do lol)

    So. For basics:
    1. I assumed step/direction control would lose me an axis, I don't, I'm a dumbass, nuff said.

    2. It's a 2500ppr encoder, quick calculations suggest at least 150khz needed so bye bye parport and hello UC300eth. I feel the 400eth is a bit port limited, especially if I end up with 5 axis and a tool changer (unlikely but I wish). I did look at the Pokeys57 but I wasn't convinced with support and being mach limited.

    3. Thinking of putting it in hybrid pos/spd mode and wiring it both ways step/dir on 5V, analogue 0-10v, DI/DO on 24v. I can then switch between the 2 depending on application or whichever is more accurate. YES?

    4. Will fit a small button control attached to machine enclosure for srv on/off and reset. Software will be in estop unless servo is enabled/on.

    5. UCCNC looks pretty good on paper. 300eth gives me the option of uccnc, mach 3 or mach 4.
    Am going to partition my PC into a triple boot using win7 (I hate 10!). Trial all 3 on their own partitions to avoid conflicts and go with the one I like.

    What's best for PC communication via LAN controller. Is the onboard fine or should I go with aa pci card?.

    Thanks.
    Daz.
    Why waste your time both ways will have the same accuracy, is your Encoder incremental or absolute
    Mactec54

  14. #14
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    Re: Servo Drive Controls I/O

    Quote Originally Posted by mactec54 View Post
    Why waste your time both ways will have the same accuracy, is your Encoder incremental or absolute

    Encoder specifics in the manual are:
    2500 p/r (resolution:10000) incremental encoder.

  15. #15
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    Re: Servo Drive Controls I/O

    Well. I made the decision.

    Ordered the UC300 + 2* UCBB boards + UCCNC lic, and all needed ribbon cable from CNCdrive.
    Got a couple of standard screw terminal header boards coming from aliexpr too for IDC26, IDC16 & Dsub15.
    The deeper control box I got fits the servo drive so I can get everything in there.
    However. With all these bloody circuits, connectors, relays etc it looks like I'll have to stack boards. That's a pain.
    I don't really need it all in there but I thought, future proof it so I never have to take it apart again (unless there's a failure).




    The missus better not look up how much this 'hobby' costs!!!

  16. #16
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    Re: Servo Drive Controls I/O

    Took 2 days to receive the uc300!!!
    Can't even manage that speed ordering from uk itself half the time

    Still too scared to fire this thing up lol. I've almost got everything together to start on the new box.
    Gone over the servo manual for the 100th time and.......
    I was going to try it using step / dir control but......
    Apparently I need a line differential for the encoder output. CNCdrive have one as a module. Didn't order one with the other stuff.
    I'm a gimp!!!!
    Can't really find anything remotely like it (simple plug and play) in the uk thus far, but looks like I can use high speed optocouplers. I'll get an opto module and try that.

    QUESTION. Where would the CZ connection go if using opto's? (pin 15). Diagram pg24, opto pulse feedback wiring pg 14.
    http://servo.xlichuan.com/Private/ProductFiles/636966428836753446713131150.pdf


    Edit. After reading a different servo book. That one says CZ is a reset, yes? Says I can use that to basically tell the servo where it's zero point is. Am I reading that correctly?
    (Using a controller input via optocoupler)

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    Re: Servo Drive Controls I/O

    Hi,

    Can't really find anything remotely like it (simple plug and play) in the uk thus far, but looks like I can use high speed optocouplers. I'll get an opto module and try that.
    Why??? You don't need it, almost all the inputs to the servo drive are ALREADY optocouplers. The servo manufacturers are trying to make their devices as easy to use as possible,
    so don't you think they would build in an opto if they thought it needed one?

    Craig

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    Quote Originally Posted by joeavaerage View Post
    Hi,



    Why??? You don't need it, almost all the inputs to the servo drive are ALREADY optocouplers. The servo manufacturers are trying to make their devices as easy to use as possible,
    so don't you think they would build in an opto if they thought it needed one?

    Craig
    My theory is it"s because the encoder output is 5v but my bob inputs use 24v. The 2 different voltages need isolation from each other.
    That"s all I can figure.
    It mentions I can use either a 26LS32 chip or optocouplers. I'll leave it for now.

    Daz.

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    Re: Servo Drive Controls I/O

    Beckhoff Automation released the EL7201 servo terminal for the EtherCAT Terminal system. The EL7201 terminal integrates a complete servo drive for motors up to 200 W into a 12 mm I/O terminal housing. Integration into the EtherCAT I/O system considerably simplifies cabling and commissioning while reducing cabinet size requirements and costs.

    The EL7201 servo terminal made its formal North American debut at the Pack Expo 2011 trade show. The EL7201 servo terminal with resolver interface features a compact design. The integrated fast EtherCAT control technology, with field-oriented current and PI speed control, supports highly dynamic positioning tasks. Apart from the direct connection of a motor and resolver, the connection of a motor holding brake is also possible.

  20. #20
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    Re: Servo Drive Controls I/O

    Hi,

    My theory is it"s because the encoder output is 5v but my bob inputs use 24v. The 2 different voltages need isolation from each other.
    That"s all I can figure.
    But the encoder plugs into the servo drive, not the BoB. The encoder of the servo is surely matched to the servo drive.

    Craig

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