Simon
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Posts posted by Simon
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I might be coming in a bit late on this one, but I prefer UniCAN to link the PLCs in this way. The main advantage is that UniCAN can be event-driven from either end. Modbus must be polled using a master/slave arrangement. With UniCAN either PLC can send changes to the other PLC as soon as something happens. Also the CANbus hardware is on the V1040 PLC as a built-in option, which leaves your serial ports free for other uses.
On this final point I am willing to be corrected, but I also think the CANbus physical layer is slightly easier to deal with than RS485. Just follow the rules, use the proper cable and it usually works. RS485 works well once it is up and running, but can be difficult to figure out initially.
As with Modbus, there is a webinar:
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I have assumed the boot time would be reduced with ongoing development. It would be good to have some feedback.
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You can also try 3rd party Bluetooth serial adaptors. So you can walk up to the panel with a laptop (or Windows tablet PC, running full version of Windows, not tablet version), link to the bluetooth, download the data via the SD card Explorer and SD Card Manager as above.
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In addition to the point that Joe mentions:
Can you hear the relays click?
I note you are using a 12V test LED. This may be just what you had on hand for testing, but note that the module requires 24V on V1 and V2.
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Looks like there is more to this than meets the eye.
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1. Only digital inputs and outputs will appear in the I and O operands. Analogue I/O don't appear unless they are configured, and once they are configured they appear in the MI section, based on which MI is linked to the each analogue input or output. The presence of the EX-A2X is assumed, so it doesn't appear explicitly in the HW config.
2. You can't save directly out of Visilogic to a removable drive. This is a known characteristic. You can achieve your aim by saving the file, closing Visilogic and then using Windows Explorer to copy the file to your removable device. Do the reverse at the other PC, copy the file off your removable device before opening it with Visilogic.
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As Joe has illustrated, you set the cycle time as a constant (and by inversion, this sets the frequency of the PWM output), then the heating effect is modulated by the duty cycle (or duty ratio as it is sometimes called).
A shorter cycle time will give your heater a faster response, but shorter lifetime of the switching device (in general terms).
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The 0V of the PLC analogue out is the 0V supply terminal - the analogue out is not galvanically isolated.
You may be able to get it working, but there are possible signal isolation issues.
Do you know if the ground (0V) of the 10V signal is isolated from 0V (ground) of the drive auxiliary supply?
Are you using the same 24V supply for the PLC that is used for the auxiliary functions on the inverter drive?
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Looking at this from the level of general concepts, Autotune enables the PID controller to learn the characteristics of the system (for example, thermal mass, lags and delays, and so on). For your 10 loops, if the charactersitcs of all 10 systems are the same, then you should get a reasonable result by tuning just one of them and copying the values to the other 9 (make sure you include the "vector of 32 MIs" in what you copy).
Likeise, if your system doesn't change much over time, then there unlikely to be a need for retuning each time.
Of course the opposite is true. If your 10 loops are quite different, then each needs to be tuned separately. If your system changes over time (for example the thermal mass changes, due to different loading patterns) then you may need to re-tune for different loads. These parameters can be saved and recalled. So you may be able to tune for "light load", "Medium Load" and "Full Load" (as examples) and save the values for future use. I am thinking of an oven or kiln in this example.
I hope this helps.
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Going back one step, also follow the same procedure of disabling the UAC as was necessary for Windows Vista and 7 (there is a sticky post in the this forum on that procedure).
As far as I am aware, the UAC issue and the "Run as Adminstrator" issue are the only two points to note when installing under Windows 8.
Are you running 32-bit or 64-bit?
If things haven't gone well, I would suggest
- uninstalling all Visilogic software
- deleting the folders as detailed in this post:
- checking the UAC is disabled. Reboot if prompted.
- reinstalling the Unitronics software.
I hope that helps.
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Thanks Joe :-)
Yes, I am assuming Ben either has some ability to carefully test and work things out, or will run away in fright. As per the first paragraph of the original post, it sounds like an experimental test bed.
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With Visilogic in Windows 8 it is often necessary to set it for "Run as Administrator". I haven't tried DataXport but your problem sounds like it could be the same issue.
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I probably over-simplified on connecting NPN signals of devices with different supply voltages. Note the V130-33-TR20 states the following voltage ranges for the NPN high-speed input:
20.4-28.8VDC for Logic ‘0’
0-3VDC for Logic ‘1
A sensor powered from 8V is not going to generate this voltage range.
As a result, either a 24V sensor is needed or use an interface relay, which would need to be a high-speed solid-state type, or an optocoupler.
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Joe has provided an excellent summary.
Unitronics will continue with the existing product range, and in my thinking, for smaller systems the V130/V350 will still be the first choice. For larger screen sizes, we will have the option of Vision or UniStream.
The UniStream is a re-creation of the Unitronics concept using current technology that is available now. As a result it will have many improvements over the Vision/Visilogic platform and will also do certain things that the Vision families cannot do. Joe has summarised some of these points.
As you get to know the UniStream product in greater detail, it will become clearer which applications will require it. In certain applications you may have the choice to use UniStream or Vision, and the decision must be made on the relevant factors for that application.
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Over all, I can see the challenges here, and as you say it's a case of which ever way you turn there are complications.
Just a comment on the sensors that output an analogue value via duty ratio, you won't pick this up with a high-speed digital input - as the frequency will be constant. Once again we get back to custom interfacing, and you should be able to interface a duty-ratio signal to an analogue input. You may need to add an RC circuit to smooth out the PWM and give a stable analogue reading. Since the sensor is chopping an 8V signal between 10% and 90% duty ratio, you should expect an analogue voltage between 0.8V and 7.2V. A 0...10V input can read this.
Your 0.5 ... 4.46V temperature sensor can go directly into the 0...10V analogue input, and you can scale the internal value accordingly. The IO-AI8 has 12 or 14-bit resolution, so you can still get reasonable resolution with the reduced voltage swing.
On the speed sensor, 3-wire is definitely simplest. If you can't get one that operates on 24V, go for an NPN one (ie, one that switches between signal wire and ground). With that type of sensor you should be able to supply the sensor with one voltage (eg 12V) and connect it to a PLC running on a different voltage (eg 24V). You can't do this with a PNP sensor (one that switches between the signal wire and Positive supply).
I see no problem using analogue sensors with a 5V or 8V supply. You just need the relevant DC-DC convertors to generate those supply voltages from your truck supply. As discussed above, just connect the 0V/Earth/ground/chassis together so everything shares a common reference point. Use a "star" arrangement on the 0V/GND to ensure each device and power supply only has a single ground point. This is necessary to avoid ground loops, which will amplify noise and disturbances on the system.
I would also use a 24V-24V DC-DC convertor on the PLC, as automotive electrical systems can swing well beyond the 24V +/- 10% required by the PLC.
Based on the discussion above, I think you have a reasonable chance of getting those sensors to work on the V130, with some relatively simple custom interface wiring and provision of the correct power supplies. The advantage of using a PLC instead of a microcontroller is significant when it comes to simplicity of programming and interfacing.
To suggest another alternative:
A step in between using the PLC on one hand and an Arduino on the other is to look for a CAN J1939 input block, that directly accepts the type of signals you are using. There are modules designed to do what you are attempting, that is retrofit digital instrumentation to an existing engine. You would need the V100-17-CAN module for the V130, and it should be easier to get the J1939 working on the V130 than it would be to program an Arduino from scatch (famous last words...). I have dabbled in J1939 and know of others who have gone deeper.
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Search "long integer" in the U90 ladder helpfile and have a play with SB82.
I think it will probably do what you need, that is place a long integer in two consecutive MI operands. It looks like the drive handles "longs" the same way. You may need to pay attention to the word order - whether the high word or low word comes first.
I hope this helps.
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It sounds like you are setting up an initial test so forgive me if this question is too basic - have you downloaded the Visilogic project to the PLC (it is a common first-time error, when just testing I/O modules). The project containing the I/O configuration needs to be downloaded for the I/O module to function.
Other than that, check everything again
* jumper settings
* configuration in Visilogic project - HW Configuration - input type set to TC type J
* wiring for TCs is simple, but check again that you have the correct terminals, etc. Make sure the terminals are plugged all the way in.
* check your TCs with a multimeter on mV setting.
* with power off, remove the snap module and re-attach it, to make sure it is connected.
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I am sure it is on the "to do " list...
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Just check the current rating - the relays (O2-O16) are 3A but transistors (O0 and O1) are only 0.5A (from the datasheet).
Also make sure you have a flywheel/freewheel diode on the solenoid coil. (see the section "Increasing Contact Life Span" in the datasheet)
if the solenoid requires more than 0.5A you will need to add an interface relay between the PLC transistor output and the solenoid. I would suggest doing this anyway if possible, to give yourself some insurance.
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We find that Unitronics is a very good platform for people to learn PLC programming. Just take your time and look at the many examples provided with Visilogic (in the "Help" menu).
The PLC is designed for industrial sensors, with 24VDC supply. However you may be able to get it working with some clever wiring. For digital sensors I would try to use NPN wiring, so you can decouple the sensor supply voltage from the PLC supply voltage. However you will need to keep the 0V common across all supplies. If you are experimenting it may be worhtwhile to get some interface relays to save you damaging the PLC while you are experimenting. Ditto for the analogue signals, get at least one external isolator, so you can figure out the signal before trinyg to connect direct to the PLC.
If you don't have one, get a good quality mutimeter.
Just a couple of comments:
- Mag pickup - this would be a "high speed" input. Sometimes these need power, sometimes they are "self energising". I am not sure how to determine this, other than go back to first principles and do some testing with a multimeter or oscilloscope of you have one.
- Pressure - 8V supply, you would need to figure this out. Put the 0V in common with the 24V PLC supply. is the output 0...8V also? This will be fine for a 0...10V input, you just won't get full range. If you have a particularly unusual signal type you can purchase programmable external analogue signal convertors.
- Temp Sensors - hopefully they are thermocouples. If they are they should give a mV output that varies with temperature, and can be measured with a good quality multimeter. The tricky part will be identifying the type (J, K, T, N, etc). If you can measure the mV at a particular temperature you may be able to cross-reference. They could also be PTC or NTC devices, and with them the resistance of the device changes with changing temperature. You can also measure this with a mutimeter, on resistance mode. There are various types of PTC and NTC devices, and not all are standardised. Some common standards are PT100 and PT1000. These are linear, and directly supported from Unitronics. However in low-cost applications, it is common to use other devices that are not linear and don't comply with any type of standard response curve. In that case it is probably less hassle to replace them with a thermocouple or PT100 - just ensure you get the right probe for he job, particularly on the 800degree location.
I hope these comments help.
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Sounds like you are heading in the right direction.
As for counters, an MI integer value will just keep going to 32767 (or 32768 - I can't remeber without looking it up), then will wrap to the -32767 and count back to zero.
So you won't actually get to 99999 using an MI, that is just the placeholder that the system uses within the HMI editor. If you want to go beyond 32768 then use an ML value.
To prevent the counter going past your upper limit, got to the ladder program and use a Compare function (Greater Than or Greater Than or Equal To) to detect when the count has exceeded your limit. Then use a store function to reset the value to your starting point. If your starting point is 0 then you can use the "Reset Numeric" function ( ---[R]--- ) instead of the store.
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This seems like a simple problem, and as you suggest, a full system initialisation is a "brute force" solution.
There is probably one value that needs to be manually cleared to give you what you want, or possibly some small change to your logic.
If possible, post your code.
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If you want maximum flexibility I would suggest setting up a dual logging arrangement. That is, set up a data table log in parallel with the trend, and log the same values using both methods.
Use the trend to put the values on the screen, and save history. Then use the datatable as a backup, where you can hold a buffer of data on the PLC and only delete if after you confirm it has been copied to the SD card.
There is no way that I am ware of where you can take data table information and load it back into a trend function. However at least you would have the data and could retrieve it and view in Excel (or similar).
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I put the label and I jump to this label until my condition is respected?
Yes, that is the essence of it. As Flex727 has indicated, it is essential to understand the fundamental concept of the PLC scan. Using a loop to some extent violates the concept of simple, repetitive scanning. With the loop you are asking the PLC to repeat a section of ladder code over and over within a single scan. This is good to get your loop executed quickly, but it will delay the PLC scan while the loop is executing. If your loop gets too long, you will trigger the PLC watchdog timer. This timer detects if the PLC scan is taking too long, and will stop the PLC if triggered.
Having said all this, the loop can work well for you if you can "tame the beast".
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Visiologic swapper problem
in Vision & Samba PLC + HMI Controllers & VisiLogic Software
Posted
Make sure you use the right shortcut when starting a swapper version. If you install, let's say, Visilogic 9.5.0 from the web it will create a start menu shortcut. If you then swap to 8.0.1 the original start menu shortcut won't work as it still points to 9.5.0. The way around this is to click "yes" on the option at the end of the swapper process to "Create shortcut to registered verison on Desktop". However make sure you keep deleting the old shortcuts to help you keep track of which one is active.