Simon
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Posts posted by Simon
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OK, so after a few false starts, it is working. It looks like the above quoted comment from the help file was cut and pasted from the ModbusRTU help section.
As discussed above, UDP is the simplest setup.
Also
- In the master modbus config, set up a slave definition with IP address of 255.255.255.255. Provided there is only a single modbus slave device at each IP address, then leave the Slave ID at 255. Use this slave when sending the data to be broadcast.
- Set both master and slave sockets to use UDP
See attached programs, they are very basic, just enough to show that this works. Visilogic version was 9.2.0. One master (V570) and 3 slaves (V130, V230, V530)
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When you say the Help file, I presume you mean:
Note that a MODBUS master can broadcast to the MODBUS network by writing to Slave ID # 0. To do this, indirectly address the Slave ID to a register, and write 0 to that register.You also need to have the correct network configuration to support the broadcast. If you are using 4 slaves or less, you can use TCP connections, and you must establish a separate socket connection to each of the slaves before initiating the broadcast.
If you have more than 4 slaves you must use UDP, in which case you don't need to perform any socket connect functions, as UDP is a connectionless protocol.
I am setting up a test and will post my results.
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Hi James,
It's not possible to open two projects. However you should be able to copy to clipboard, close the project, open the other project and then paste. I know this isn't as simple as we would like but it is at least an option.
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Colour LCDs work by filtering the white backlight to produce colour. The backlight is always on and the active LCD layer is used to block or allow light to pass through the red, green and blue filters. Each pixel is a group of these filters. For example the red colour is produced by switching on only the parts of the pixels with red filters. One weakness of LCD is that when the pixels are switched off a very small amount of light leaks through, so in the case of red colour, there would also be a very small amount of green and blue emitted. THis would also be the case for the "black" areas of the screen.
As Emil suggested you can also adjust the backlight intensity to its minimum usable level.
If they use B&W mono screens then it sounds like some stray light is OK. But maybe they have a way you can run some tests?
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Hello stembera,
Contact your local distributor for their help. It isn't a repair that can be carried out locally.
(I work for the Australian distributor of Unitronics)
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Hi Reuven,
When checking comms to the PLC it just brings up the progress indicator and hangs in that state.
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Hi Alan,
That temp range should not cause any problems. Please email me through my profile if you want to discuss options to get this fixed.
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I am interested to hear of user experiences with the EEEPC and Windows 7, and Windows 7 Starter in particular.
A user has had no problems with Visilogic, but lots of problems running UniVision licensing, particularly with USB to serial.
I look forward to hearing of scuccess or otherwise using this combination.
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FWIW I powered one up on the desk with no addtional housing, just the PLC as shipped. Ambient is around 20-22degrees and the reported temp on SI14 rose to about 28degrees. So the offset from ambient is not unexpected, but the large variation is less easy to explain.
My reference is an old V120-12-UN2 with a thermocouple attached.
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Hello Alan,
It's not a common problem, but is unlikely it could be repaired on-site. The only user-accessible setting is the backlight intensity SI value, which you have checked.
I don't know the specified lifetime for the backlight, but you should expect many years. This will be less if the unit is exposed to temperatures outside the operating range, particularly at the higher end.
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Hello Stein
Although I didn't ask the original question, let me point out that the question relates to the use of the internal temperature sensor, accessible via SI14. The snap-in module is not being used to measure temperature.
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OK, so sounds like something is not right.
Do you have any V570 units that record the correct temperature (or close to it)?
Are you saying that you have two V570 plcs that are showing temperatures that are both way off, and they are also quite different from each other?
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Just a simple check, make sure you are using 57,600baud or lower. Newer versions of Visilogic will default to 115,200baud. The V280 will start to communicate at that speed, but will lose the plot at some point.
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Hi John,
The V570 develops more heat than some of the older models like the V290. If it is locked in a box the internal temp may get noticeably higher than ambient, particularly if the box is sitting face-up rather than vertical.
Does this tally with what you are seeing?
Simon
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Thanks Cara, but that one seems also to be suffering the same malaise. I have the 9.2.0 beta, so will wait a couple of days and try again.
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Looks like everyone is downloading...9.76kB/sec. Maybe the server needs a cigar and a good cup of coffee?
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Excellent!
Joe, there must be a way to distill the creative energy inherent in cigar smoke into some other form.
Please get to work on this; I could really use some...
I think it also occurs in choc-coated peanuts.
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Hello MWD,
The data table is stored in battery backed RAM, the same as the MB, MI, etc. If it is being lost when power is switched off there must be a problem with the battery - either not-fitted, is flat or the unit is faulty (the latter is least likely, but one of the possibilities). SB8 will tell you if the battery is getting low.
Since the V130 supports the SD card, you could use that.
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In my experience, remote access via GSM modem for the colour PLCs is quite slow. Possibly the response may be slightly faster using Remote Operator instead of Remote Access. However the fundamental problem is that the baud rate via GSM is only 9600. The ideal solution is to use a broadband wireless modem connected to the PLC via ethernet. If you are stuck with the GSM serial modem, another option may be to use SCADA software and Modbus.
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I get it when messing about with Bluetooth serial ports and modems. If Visilogic tries to open a COM port that is associated with a Bluetooth modem, the modem must be initialised, or it all goes down in a heap.
I have had a similar experiences with a virtual COM port, but after the first time I just avoided the situation, so don't have much info on that one.
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Hello Fabio,
I think you are doing a good job of finding all the problems!
If you are using a standard input then the fundamental limit is the speed you can read the input. This is either the normal PLC scan, or you can use the 2.5ms or 1.25ms interrupt routines (depending on the model of PLC you are using). This still isn't fast enough for your pulses, based on the figures you provide above. This is the problem for the high-speed range.
You have already looked at the low-speed range and ruled out using more bolts. However that is really the only option to improve resolution for low-speed frequency measurement using a high-speed counter.
Here's a thought. Note that when you configure an input as a high-speed counter, you can also still read the immediate value of the input, as a normal digital input. For low speeds you read the input directly in logic, as you have been doing. Then for higher speeds you can read the High-Speed input.
There are definitely some potential problems with this approach, but maybe it's just crazy enough to work...
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From the datasheet, the response time is 10ms on all inputs, except for input15 when it is confiugred as a High-Speed input.
I had to read it a couple of times to be sure, and from the wording of your questions, sounds like you had the same issue.
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Joe, when the relays wear out, can I replace them with replacement relays from Unitronics? Or do I have to replace the whole printed circuit board, or worse, the whole V130 PLC?
I'm not Joe, but usually the official line is that you would need to send the entire PLC back to Unitronics for repair.
However, Unitronics usually list the manufacturer's part number(s) of the relays in the PLC datasheets, and they aren't too hard to find in stock at general electronics suppliers.
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UDP conflict with TCP?
in Vision & Samba PLC + HMI Controllers & VisiLogic Software
Posted
In general terms UDP traffic should co-exist quite happily with TCP traffic. This is what happens on the internet all the time. WIth TCP the data is acknowledged and re-sent if lost. However with UDP the data is simply sent, with no ack or retransmission. The UDP traffic will most likely suffer first if the network becomes congested, since there is no acknowledgement. This also means that UDP will impose less overhead on the network as it doesn't generate the additional traffic required for acknowledging each packet.
If you need some form of "i'm alive" signal back from the UDP slaves, then you should include this in the logic of your Visilogic projects.