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Simon

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  1. I'm not aware of anything built-in. I do it manually, and when it comes up as an issues I advise others to do the same. Do it at least once per day, and ecah time you add a new chunk of functionality, or attempted bug fix.
  2. Hi @Cara Bereck Levy I would agree with the above from @Joe Tauser and @Ausman. The way the ranges are currently expressed in the datasheet are scientifically correct (15 bits : 0.61uA/Bit(0~20mA), 0.49uA/Bit(4~20mA)) , but takes a few steps of logic and caulculation to turn that around to something that is useful for the programmer. It should be expressed in terms that apply directly to the programming, as @Ausman has done. The sign bit is meaningless if the signal is always positive or zero.
  3. When using the high-speed input there is dedicated hardware to peform the pulse counting and frequency calculation. This is independent of scan time. The high-speed counter input is looking only for edges (or change of state) of the input signal. So does not matter if the one pulse per rev is the closed or open state. Just to re-state again, you are registering 190Hz with the sensor in the closed state. Following from the above point, this would suggest the sensor circuit has some noise on it that is being counted. I looked again at your first post, you say "black wire to I0, the blue to 0V and brown to common". I should stop there, brown wire is positive supply and should go to 24V. The fact that you see the LED switch seems to indicate the sensor is powered correctly, but it pays to double check. The other thing you can do is replace the sensor with a piece of wire - that is, put a piece of wire into I0. If you hold the free end onto the 0V terminal or leave it open circuit you should get 0Hz. If you rapidly touch it on and off 0V you should get something like 5-10Hz (do this safely of course, perhaps a mechanical switch could be used that you can flick on and off rapidly). Hope this helps,
  4. I would also suggest interposing relays, I think that is an all-round better option than introducing another programmable device.
  5. I think the clue about the span of values is here: 15 bits : 0.61uA/Bit(0~20mA), 0.49uA/Bit(4~20mA) The uA per bit is different depending on the range. I think that the mention of the sign bit is superfluous (and therefore confusing) as the module only has unipolar inputs. I think experienced Unitronics users are conditioned to expect a 4...20mA analogue range to not use the full span of the digtal word, based on experience with other Unitronics families. But as Flex has commented some Vision modules (mainly outputs) will use the full digital scale regardless of whether they are 0...20mA or 4...20mA.
  6. The other thing you can do to score a few confidence points is to use a PC-based Modbus tool. There are master and slave programs available. One example as follows: https://www.win-tech.com/html/demos.htm You can test: Unitronics PLC master to PC-Simulator Slave PC-Simulator Master to VFD Slave You can also try PC-Master to PC-Slave and even PLC-Master to PLC-Slave (using two COM ports). In each case the goal is to confirm that at least one side of the communication is working OK, by process of elimination. The V570 also has a built-in COM port sniffer, so you can monitor the traffic. It is accessible thorugh the info mode. It will be all HEX data, but at least you will be able to see if the drive is responding or not, as the TX and RX data are displayed separately. The issue may be as simple as just swapping RX and TX wires. The most frustrating thing about debugging comms is the way it can all just sit there not working, and you feel like it's all a dark secret. Use any trick you can to "open up" the system and let it show you where the problem is.
  7. No worries, my pleasure. And yes, local Modbus comms is definitely another complicating factor. It's a bit like the old riddle, I have a fox, a chicken and a bag of wheat, I need to cross the river, but my canoe can only take 2 things at a time...
  8. Note also that you can use an ethernet modem and a serial modem simultaneously on the V350. I have seen applications that do this. The obviously (and only) downside is the need to have 2 modems and 2 SIM cards.
  9. Hi Joe, I've worked with modems and communications on Unitronics for many years. They do certain things extremely well and we have seen many successful applications. More detailed comments and advice are below: 1. Ability to log in to the PLC Web Server - This is the most difficult of your 3 things to achieve over GPRS. You need at least a public, dynamic IP address. Once the GPRS connection is active, you then need a way to find the current IP address of the modem. One option is to get the PLC to send its IP address to you in an email once it has connected to the network. Note that this is not secure, anyone who figures out the IP address and what device is at the oter end can start to try and access it. 2. Ability to send a weekly csv. file via email - this works reasonably well, the nice thing about sending emails is that the IP address does not need to be public. However with the Vision family, you need an email server that can accept unencrypted connections. 3. Ability to send text msg for alarms - by far the easiest thing to do with the EHS6T and a V350. I would only recommend this modem to do SMS and nothing else. Trying to mix GPRS and text messaging is not simple, as the PLC to Modem communications has to be reconfigured for each mode (SMS or GPRS). Overall I found GPRS to be a fragile and difficult method of setting up a data link. If you want to use the web server, I would recommend switching to an Ethernet modem, which would also require the V100-17-ET2 card for the PLC. With ethernet you can do things like Dynamic DNS or VPN as a way to maintain a connection to the unit's IP address. However when switching to Ethernet, there is no easy way to keep using the SMS feature at the same time. The simplest workaround for that is to send all alarms by email, as most people now receive emails on their phones. SMS is beleived to be "reliable" but the SMS standard allows 24 hours delay in delivering the message (I heard a rumour that has been increased to 48 hours). In short, from my experience, it's not possible to do all 3 tasks that you have described with a single device/single connection, using just the standard built-in features of Unitronics. If anyone can improve on my advice, I'm happy to be corrected.
  10. Hi Joe, It sounds like you are setting up GPRS. There are a number of steps, and Unitronics provide an example program. A lot of PLC programming tasks can be solved by trial and error, I don't recommend that approach for GPRS. Find the example and understand it. They are installed with the Visilogic installation: C:\Program Files (x86)\Unitronics\Unitronics VisiLogic_C\Examples\Version 900\Project examples\Communications\GPRS Specifically on your question. the APN is entered in the "GPRS Register to Network" function block: I hope this helps,
  11. That is a different issue, the details on the screen are different. In your case Fernanda, the PLC has lost it's Visilogic project. The most likely reason is that the on-board battery is flat (check the value of SB8) and the project was not originally downloaded with either the "download all and burn" or "Burn upload project" options.
  12. Has anyone had trouble printing from U90 Ladder? It isn't something I do very often, but I wrote a little program for a customer and wanted to print out some key sections. I tried printing to 3 different PDF printers, as well as the office hardcopy printer. I also tried printing via the Print Preview screen. When I hit print it sits there for about 20 seconds, then appears to print something but nothing happens. In the case of PDF print I get no dialo box to enter a filename, for physical printer, there is no printout. Using U90 Ladder 6.6.45 and have run the patch on my PC to fix the recent issue with Windows updates. At this stage it's not a crticial issue but I would be interested to know if anyone else has experienced this, and if there is a simple fix. Thanks,
  13. I expect the loadcell is used to measure the tension of the web. I would have some concerns over the V130 PID being fast enough to control this loop. Happy to have those concerns overturned by the experience of others though 🙂
  14. Hi Nahum, Thanks for the advice. I also did some testing using a PC based Modbus master simulator (ModScan) and confirmed the situation as well. I also found that there was an offset of 1 between the internal UniLogic address value (in the Modbus Slave configuration) and the external Modbus address. For example coil register 9472 appears as 09473 (Read Coils (1)) or 19473 (Read Discrete Inputs (2)) I think it would be a valuable addition to have an explanation of this in the UniLogic help file under Modbus Slave. For example: Coil values can be read using either Read Coils (1) or Read Discrete Inputs (2). For example coil address 4444 can be accessed as either 04445 (Read Coils (1)) or 14445 (Read Discrete Inputs (2)) Register values can be read using either Read Holding Registers (3) or Read Inputs Registers (4). For example Register address 1111 can be read as either 41112 (Read Holding Registers (3)) or 31112 (Read Inputs Registers (4)) Maybe add a configurable offset value to UniLogic, so this offset can be corrected in future applications, without destroying backward compatibility?? It has always been a common "gotcha" with Modbus, to discover who counts from "0" and who counts from "1". Thanks, Simon
  15. Hi Jota, thanks for the reply. I expected more people to jump on this. I also found the offset of 1 between the PLC address and the SCADA address. In my case the customer had a list of SCADA addresses they expected to see, so in practice I needed to subtract 1 from the SCADA address to get the internal PLC address. I had no trouble with using the Slave ID of 255 on both the PLC and the SCADA. I did my testing using ModScan. More details from me below. Simon
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