Kikis
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Posts posted by Kikis
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6 hours ago, Flex727 said:
Looks interesting. Can you provide a link to the product?
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Hi guys,
I usually use this type of transistor board to isolate the PLC outputs from the controlled load.
It can switch 3A per channel with 1KHz switching frequency while current draw on PLC output is a few mA.
For the 10 channel board, the cost is something like 17 USD.
It's significantly cheaper than using relays and requires much less wiring.
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I think it works like this:
4095 you get +10V, -4095 you get -10V
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Hello,
I guess that your V120 will be the Modbus slave, so you can check the example included within Visilogic.
There is also a Unitronics webinar about Modbus that will be very helpful.
Regarding Redlion HMI, i can't help you as i have never used their products.
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Hello,
If your screen supports modbus RTU, it would be very easy to establish communication via RS-232.
I did this many times in the past with V120 - V130 PLC's and Samkoon HMI's.
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Hi Guys,
I have a new project which includes among others, the control of five independent servo motor axis for point to point positioning.
I want to use a V1040 PLC and control Delta ASDA A2-M servo drives via CANopen protocol.
Has anyone any experience of "talking" to Delta servo's with CANopen by a Unitronics PLC?
Any feedback would be greatly appreciated!
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Hello,
It seems that you got the wrong Samba model as T20 has no analog output.
The samba models which have 2 channel analog output are TA22 and RA22.
"T" stands for transistor type digital outputs and "R" for relay type.
Btw the spec sheet you are referring to is for RA22 model, not for T20.
There is not just one Samba model but various models with different I/O points on board.
Therefore every time you have to select the right model depending on your application.
You can find all available Samba models and their I/O details on Unitronics Website.
I/O points for each PLC model can also be found in the hardware configuration within Visilogic.
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Hello,
Make sure that the sub-routines are called within the main routine of your program.
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Hello,
Alarm aknkowledge is done by pressing F2 button on the keypad.
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Hello,
Use a self-resetting timer with 1 min preset setting (attached example) so that you get a pulse every minute.
Then replace SB13 with the direct contact of this timer.
SD card's free space is shown in SBW 59. Capacity is given in 512-byte chunks.
Note that you have to SET SB 217 to enable writing into SBW 59.
Then just link SDW 59 to a numeric entry variable on the screen.
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13 hours ago, gdamat said:
Regulator must have LED display and control buttons to change parameters . Regulator has to have a real-time clock and communication channel for data exchange with PC. In case of power loss the regulator must ensure the preservation of parameters in memory.
You can select a model from the Vision series, depending on the size of the touch screen you need.
Vision models offer RTC, communication options, retentive data values and much much more.
Since you know the exact I/O requirements for your projects, you can select I/O expansion modules to connect to the PLC via EX-A2X adapter.
You have also the option to add I/O by using one snap-in module (attach to the back of the controller).
All details about PLC's and expansion modules can be found very easily on Unitronics website.
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I usually use an analog output which i program to continuously output 10V as reference voltage for pots.
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Hello,
If the pressure is linearly proportional to the analog input voltage, then you could use linear interpolation formula and floating point registers (MF).
Floating registers are also known as real numbers and it's the best way to deal with fractions.
Since the linearization function within Visilogic can't be used for MF registers, you have to do it step by step using simple mathematical functions.
LINEAR INTERPOLATION FORMULA:
Y = ( ( X - X1 )( Y2 - Y1) / ( X2 - X1) )
Where,
X1,Y1 = First co-ordinates
X2,Y2 = Second co-ordinates
X = Target X co-ordinate
Y = Interpolated Y co-ordinate
If your 0-10V analog input is 12 bit (0-4095) then,
X=Current analog input value linked to an MI
X1=409
X2=3726
Y1=0.000055
Y2=1000
Y= Pressure result displayed on the screen
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Hello,
12VDC can't be used to feed the outputs on this PLC model (JZ20-T40).
The nominal voltage for both output groups is given by specifications to be 24VDC (20.4 - 28.8VDC).
If you want to control 12VDC loads with this PLC, you have to do it indirectly by using relays.
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On 9/20/2016 at 2:07 AM, Joe Tauser said:
12V PLCs are kind of hard to come by, especially one with any kind of capability. Plus, this is the Unitronics forum so it's kind of blasphemous to recommend competitor's products. I have used one of these 12-24V converters when I've done a vehicle application:
They work quite well, and now you can use any of our products.
Joe T.
+1 on Joe's suggestion.
I have also used this kind of DC step-up modules many times in the past with no problems.
They are cheap and reliable. I think it's the best solution when 24VDC power supply can't be used.
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Hello,
There is a com port initialization function block in Visilogic where you can set all details related to the selected port.
Use this function block at the beginning of your program with direct contact of SB2 (Power-up pulse) as a condition for the command to be executed (attached photo).
Unitronics help page for Com Init:
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If you have linked MI0 to AN 0 and your wiring is correct then it should work.
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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.
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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.
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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.
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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.
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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.
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.
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You can follow the dropbox link below to download an example i have made based on your description.
Unfortunately the file is too big to be attached here.
https://www.dropbox.com/s/hn07kywo7a8kmto/RADIO%20BUTTON%20SAMPLE.vlp?dl=0
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Hello Gabriel,
I had the same problem sometime in the past.
Finally i found out that i was using an outdated adapter driver.
So make sure that you are using the most recent driver.
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Hello,
I think the best way to to do this is to select a servo system with e-cam option, capable of performing flying shear action .
There are servo drives which support this feature such as Delta's ASDA A2 servo package.
Use your V350 to drive the whole machine and let servo controller to precisely drive the movements using electronic cam .
IO-R08 Relay Module - Output LEDs
in We're Listening...
Posted
Hi Guys,
From my experience, one should be careful when buying something from AliExpress.
Especially when buying stuff to be used in control panels for machinery and other critical equipment.
It's always a good idea to communicate with the seller before placing an order.
The site is full of cheap Chinese copies of products which look 100% original (for example, SSR's).
However, it is a safe site to buy stuff and i never had a non received order. Also never had any problems with my Visa Card.
Regarding the transistor boards, i use them in almost every project since i discovered them last year. They do the job without any problem at all.
Delivery time (Europe) is approx. 1 month.