Jump to content


Popular Content

Showing content with the highest reputation since 07/07/2019 in all areas

  1. 3 points
    Yes, it was already implemented and would be available on the next release of UniLogic.
  2. 3 points
    Just for fun, this is the control panel for a new force tester we created. If you are a Star Trek fan. I can't be the only nerd on this forum, am I?
  3. 2 points
    Hi All, We already have a solution for this case. As you can see we added the eye button option - if you will click on it the keys will not change their color/shade when pressing and the person who connected by VNC will not be able to see your password.
  4. 2 points
    I had a Hyundai Santa Fe once upon a time that strangely had the calendar date displayed on the dash. It was set with the month day and year and knew which years were leap years. However, the subroutine that it went into to allow February to have more than 28 days failed to have an exit. So, on leap years it would continue to count up from February 29th, each day incrementing up. It was easily fixed by resetting the date to March 1st, but I had to see what it would eventually do. Each day it incremented up until it hit February 99th, and since there were only 2 digits, I couldn't wait to see what it would do the next day. You would have thought that maybe it would go to 00, but it didn't. It completely lost its mind and displayed nonsense symbols every day thereafter.
  5. 2 points
    Hi, I will try to describe why it works without a connection. 1) There is output board inIside of the Unitronics OPLC controller. 2) Each of the solid state outputs is a part (one channel) of the few chip VN340SP (or something like that on foto). 3) To send signals from the processor to this chip, we must have one common wire and several separate ones for the required number of outputs. This common wire also neded for power the VN340SP. This wire is the OV contact you specified. 4) This OV contact is connected to the main power OV contact of the PLC panel through a small fuse (you can check with a measuring device that the resistance between the 0V and 0V contacts is not equal to 0 Ohm). For example i post foto of little fuse and 0V power connection for SAMBA SM70 board. That is why you output operate with 0V not connected. 5) If you neglect to connect this contact, it may happen that the fuse (or another cirquit) inside PLC blows and all your outputs stop working. Conclusion - always use the connection RECOMMENDED by the manufacturer. This will save your controller from problems and save you money.
  6. 2 points
    3 years ago I knew nothing about PLC's. Because of people like @Ausman, @Flex727, @Joe Tauser and others on this forum, we converted 8 machines from old relay logic to PLC's with automation, made 2 pieces of complex laboratory test equipment for the lab, and entire tank farm controls that include, levels, filling, heating/cooling, mixing etc. I could have never done it with their help. I don't know if they're paid or not, but I will tell you they are priceless. I hope that @Cara Bereck Levy will show this to the powers at be so they understand the caliber of people they have in this forum. It burns me, me when people are rude or "expect" someone to write their programs without giving it any effort first. Be polite, give it your best effort and people here will jump in to help you. This concludes my diatribe.
  7. 2 points
    Depending on how old the OS was, there may have been a change in how a function works. Try this, too, to see if there's some code causing the problem. In Visilogic, go to Edit->Find Sub by Ladder Error Code- Enter "7E" (your ladder error) in the popup box. Joe T.
  8. 2 points
    I typically just use SB 13 to increment an ML. You can then divide that by 360 to get you hours to the tenth of an hour for display.
  9. 2 points
    Hello, Open font handler by clicking the (A) icon on the toolbar, from there you can add a new font.
  10. 2 points
    Ok I was finally able to send email to my local exchange server account using my local exchange server. Without getting into details, my problem was in the settings that I used in specifying the Account. A logfile would have saved me a lot of effort. The following link was instrumental in digging out the answers: Microsoft : Use Telnet to test SMTP communication on Exchange Servers Yea!
  11. 2 points
    This is exactly what I had to do with Visilogic in an application that had multiple users with a couple of different access levels. As you've figured out, it wasn't the easiest thing in the world. UniStream addresses this with User Access Control that has 16 levels, 16 groups and 128 users. If this is really important to your project you may need to switch platforms. If you haven't already downloaded UniLogic I'd recommend doing so and having a look. Joe T.
  12. 2 points
    Hi HexMan, This option exist for the enhanced models – Please make sure to use the latest OS: 1 Set in SI165 the start address of MB the user will be able to access 2. Set in SI166 the end address of MB the user will be able to access 3. Set in SI167 the start address of MI the user will be able to access 4. Set in SI168 the end address of MI the user will be able to access 5. Set SB305 to activate the MODBUS limit. For example if you will set the following: SI165 = 1000 SI166 = 1999 SI167 = 1000 SI168 = 1999 SB305 = 1 The MODBUS master will be able to access only to MB1000 – MB1999 and MI1000 – MI1999. If anyway one tries to access the restricted operands SL46 will increment. You have to arrange MIs and MBs in sequence. There is ni separate limitation for read and write. B.R.
  13. 2 points
    Dear Samith Chathuranga, From the PLC POV you need to configure the mosquitto broker connection parameter in UniLogic. From the Help section:
  14. 2 points
    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.
  15. 2 points
    Spotter90, What VisiLogic version do you use? Attempt to check for OS update from Help menu, then update PLC OS with new one and test again. If this does not helps - send your request to support@unitronics.com B.R.
  16. 2 points
    I think it's unlikely we'll ever see a software simulator from Unitronics. Their programming software is free and the PLC hardware is less expensive than most other manufacturers programming and simulator software. Just pony up for an actual PLC and you'll be amazed at how well it works as a simulator.
  17. 2 points
    Hi DaveB, Look at forum topic http://forum.unitronics.com/topic/6241-read-single-precision-arrays-with-modbus-tcpip/?tab=comments#comment-25356 Does it help you? B.R.
  18. 2 points
    Hi; Been there , done that. This is a Windows related issue. There is an install shield file that has information in it causing the problem, and has to be moved or deleted. Here is a solution: CAUTION : I Take NO Responsibility for anything that happens ( good or bad)!!!!! Local Administrator privileges may be necessary. KNOW what you are doing! Open C:\Program Files (x86)\InstallShield Installation Information There are a few or many very oddly named folders e.g. {12AB95C7-C72D-4CF5-9B6D-7452DF048C56} Starting at the top, click on the folder to open it: Each folder has a group of files. Look for the file : Setup.ini Double click to open the file or open the file in Notepad ( Notepad ONLY, this is a simple Text File) Top Line [Startup] 2nd line AppName= If the App name is NOT VisiLogic, close Notepad ( DO NOT do a Save or Save As) Move on the next folder If the Appname= is VisiLogic, Close Notepad Back out of that folder, Cut the Folder and Paste it into the Downloads Folder -- Just a safe place to put it for now. Also Rename the Folder and ADD - VisiLogic Restart the VisiLogic Installation, and ( fingers crossed ) it should go smoothly. You can also run a registry cleanup program later to locate and delete unused registry entries. Dant
  19. 2 points
    First you need to scale your analog input that you have your RTD connected to. What are the specs on your RTD transmitter? From the -T20 specifications: You've mapped MI 0 to Analog Input 0. So at 4 mA MI 0 will return 204, and at 20 mA it will read 1023, which is the output from the 10 bit A/D converter. You need to know what real temperatures that corresponds to and us a LINEAR block to do the scaling before you feed it into the PID block. Read the Help on how this block works. A common spec for an RTD transmitter is 4/20 mA = 0 - 250 C. Here's how the LINEAR block should look for this scaling: The PID CONFIG block should only be called once at startup, and the input should be the scaled temperature: You have to put values in the input parameters before the PID block will function. You can use the power-up values to eliminate setting them with the program. Now the big question - do you know how PID works? The output of the block will be an analog value that will span between the Control Value high and low limits. I put some in for you, but if you don't understand what they mean you need to spend some time reading ALL the Help on the block. You'll probably have to convert the output to some kind of time proportional signal to drive a discrete output. You'll also have to run Auto-Tune or set the P, I, and D parameters manually while it's running. Joe T. Termotunel JT.vlp
  20. 1 point
    Yes, you absolutely can. You can get even more precision out of your particular setup by linearizing to 0-250 to get 2 decimal places, if needed.
  21. 1 point
    I'll tell what worked for me regarding your questions, newbie88. Steps go as you described. Connect to 1-Read-Disconnect; Connect to 2-Read-Disconnect... You are using TCP so connection is required. Delay of 0.4 seconds after disconnecting from one client before connecting to second one, and another 0.4 seconds before sending Modbus commands, maybe this can be shorter (probably, you should experiment). For 4 clients this cycle takes 3.9 seconds, if time is critical you may need to use more sockets or go to UniStream. For any slave that drops number of retries and timeout will add extra delay. I'm not sure about reinitializing Configuration FB. It does have addresses for only 15 slaves, but if I remember right when you execute read command it will read from whichever slave the PLC is connected to, disregarding the "Slave ID number" that is in the read command. Maybe this was an issue from some older VisiLogic version when I encountered this for the first time. I've wanted to test this for some time now, but don't have the will. This depends on how you make your logic. If you use that standard form from Examples You can go to next step after all read bits are low for how many read commands you have. I found it works without putting delays between commands, just using "Function in Progress" bit to stop multiple read commands from interfering one with another. Don't forget that system bit that shows if socket is connected should be a condition before blasting Modbus commands. Hope it helps, tell us how it goes.
  22. 1 point
    When you install a new version of UniLogic it asks you if you want to keep the previous version. Say yes. You will then have both versions installed. You can continue this as needed. I have 8 versions installed on my desktop right now.
  23. 1 point
    Server - it's the one "serving up" the files. Setting it up is under PLC Communications->Protocols->FTP->FTP Servers. I think you can probably handle it from there. To test it, put an ftp program on your PC like FileZilla and log into the UniStream to see all your files. Your IT guy should be able to handle getting the files off it. Unless you're the IT guy, then that's another topic. Joe T.
  24. 1 point
    With overnight pondering whilst asleep (thankyou brain), I actually think you need to change methods. A direct lift from the Jabsco sheet Kratmel refers to: I am all for doing unorthodox things, that is the way I have got around myriad problems over many years of designing lots of odd stuff. You have obviously been implementing this setup OK before. But I'd seriously consider changing the way you do it. I'd run the pumps at full speed and institute a variable valve flow system with a pressure bypass back to the respective holding tank. The pressure reliefs would be set equally so that the pumps don't get overworked. Both the valves could be easily controlled by an analogue signal which would be available on a different samba model, which would be set before starting both motors concurrently. Although this is still open loop, this method would likely give you much better flow control owing to consistency of mixing pressures. cheers, Aus
  25. 1 point
    1. You cannot power these motors by Ladder PWM SCAN FB. It is very slow for DC motors. 2. Right (MARCO) motor picture show remark "Do not use with PWM", so you should use voltage regulator for this motor. And this voltage regulator should be managed by 4-20 mA, 0-10V, or PWM signal. 3. Left picture motor may require the same regulators. *Both motors are 12V. Do you power PLC by 12 V? May be other Forum members has experience with such equipment? B.R.
  26. 1 point
    Hi CobryWZL, There are two different PWM settings, and many peoples mix it by mistake. 1. Hardware PWM, which is configured in Hardware Configuration. 2. Slow PWM Scan in Ladder. Two PWMs cannot be mixed. In Ladder you use second one. What is a PWM configuration in HW configuration?
  27. 1 point
    It seems you have some misunderstanding of how your PLC and VisiLogic operates. The program uploaded or downloaded with VisiLogic does not contain operand values. However, there is a facility to do that. Go to Connection/Export PLC Operands (to text or binary file) while connected to the old PLC. After that completes, do the reverse with the new PLC. You can also do something similar with an SD card, but the PLC program must be set up to allow that.
  28. 1 point
    That's good, Zoran. This is possibly an example of why Unitronics has Version Swapper. If you have an application that works fine on a particular O/S then there is no reason to upgrade it to a later version. Many times on the forum you will hear "If it isn't broken, don't fix it". The temptation is great to always update and run the very latest version of Visilogic, but it can often create issues. Many times "easy implementation" translates to "go backwards a bit to the older version that works". cheers, Aus
  29. 1 point
    Set up an Indexed Data Table and push the values down as they are accumulated. Then you can use the Store DTI to file function block when your logic calls for it and clear it out. Joe T.
  30. 1 point
    Go to HMI ... Font Handler menu. Then select the font you want add special characters (defaul fonts cannot be modified) and select those required characters
  31. 1 point
    Of course there is a practical limit, but I haven't run into it. When you consider that Ethernet runs at 100 Mbit/s, simple math says that in 500ms you could exchange 50 Mbits. Of course there is overhead, so I'll divide that by 2, giving 25 Mbits. Divide that by the 32 bits for your INT32 registers, then you get 781,250 INT32s can be exchanged. I'm sure there are other factors of importance here and there is a MODBUS limit of 256 bytes per request, which will be your primary limiting parameter.
  32. 1 point
    Used to have this issue on v1040s with a lot of screen elements. Clicking off of an item onto a blank space would take a while. Trick was to ctrl+click to deselect the item. Leaves you in the same state of having nothing selected, but without the wait. Nick
  33. 1 point
    In line with the suggestions by Ausman, have you also tried opering the Modbus with just the power meter and UniStream together, no other devices? I haven't really seen any issues with other devices not running the same Modbus standard as Unitronics. One thing I do notice is that different vendors use different notation for the wiring - eg A,B, D+, D- . I have seen different vendors use opposite notation. It's easiest to sort this out with two devices at a time, and sometimes the solution is as simple as swpaping the wires. Also when you get drops, what are the error codes telling you? Are they timeouts (no comms), or is the power meter communicating, but returning an error code? My experience with power meters (Crompton, see below) is that they use 32-bit floating point values, but the Modbus address space works on 16-bit words. Hence only every second Modbus address is valid. Also beware of the +/- 1 offset. Unitronics calls the first register as 0, whilst some slave devices call their first register as 0 and others call it 1. Also if you a trying to read only 1 value, you will need to read two consecutive modbus registers. If the power meter is using 32-bit values, trying to read only a single 16-bit value is likely to generate an error. I end up doing a fair bit of experimentation to find the right combination. Disclosure: My company is a Unitronics distributor and also a distributor of Crompton power meters. I have set up several demos with UniStream to a Crompton meter and got them working on both Modbus RTU and Modbus TCP. I have also assisted customers with setting up many different Modbus devices on Unitronics PLCs. So I could say Crompton meters work fine. However If you can't get 3 other brands to work, then I would be looking at the setup rather than the brand of meter.
  34. 1 point
    Milosh, Visit https://unitronicsplc.com/support-technical-library/ Expand "Jazz & M91 Hardware" Expand "Jazz add-on modules and accessories" Scroll down and open JZ-PRG Specification https://myzone-kza3sadj.netdna-ssl.com/wp-content/uploads/2016/06/MJ20-PRG_TECH-SPEC_10-09.pdf JZ-PRG Install Guide https://myzone-kza3sadj.netdna-ssl.com/wp-content/uploads/2016/06/JZ-PRG_INSTL-GUIDE_10-09.pdf Here you can find all details, include pinout. MJ10-22-CS76 internal wiring provide power to PRG module as well. *PRG module power consumption is low and used only to power RS232 communication. *When use CS10 adapter, you have to use RS232 port with full set of signals. Unitronics supply Prolific based USB-to-Serial converter supporting all signals. Other converters may have only RX, TX and Ground wires. And may not supply power to PRG module. B.R.
  35. 1 point
  36. 1 point
    You can use the built in functions to send a CSV file: HMI button sets a bit--> "Store DTI to File" Make sure to set "F" to 1 so it saves a CSV file onto the SD card--> Then when the "H" status finishes (1-->0) you can use the built in "FTP Send" to send that CSV file you named in the "Store DTI to File" Then go find it and open in Excel (import as CSV). Now if you want to import it back into the PLC after you make changes to the file you need to reverse this process: save as CSV (on computer) "FTP Receive" "Convert CSV to UDTF" "Load DTI from File"
  37. 1 point
    Hi and welcome. Before doing anything else, did you do the install as right click/run as admin? And once that is done, go to the U90ladder.exe program itself and ensure you have Run as Admin selected in right click/Properties/Compatibility. If you did not do the install as above, save your plc programs, connect the plc and manually fully delete the matching com port driver in Device Manager, completely uninstall U90 using the standard uninstaller, then delete the Unitronics U90 Ladder folder if it remains, reboot and start again, doing the install as first mentioned. In theory the latest versions of the program do the admin stuff themselves, but sometimes it doesn't work. Once you have done that, see how it goes and then we'll proceed from there. cheers, Aus
  38. 1 point
    Hi, Which version of software are you working with? Please ensure you are using 9.8.80, and then go to Help > Check for updates > Operating System. Then please update the controller's OS. There was an issue with the acceleration function block in previous versions.
  39. 1 point
    I thank the Unitronics team for making me the part of the beta project.
  40. 1 point
    I love browsing aliexpress. So many bargains! Delivery time? I forgot to look at that! I do think that adding Modbus to this mix would overly complicate the code. But it is an option. @cleman84 - I'm a Dwyer dealer and I use and recommend those CCTs all the time. When the first came out I put them on my old-tyme Fluke 760A meter calibrator in AC current source mode and found them to be amazingly accurate for the price. But as you found out - AC only. As far as making your Honeywell sensors work, I see the CSLA2DG 150A sensor you've chosen has a 16.2 mV / amp output assuming one pass of the wire through the core. Cranking the math gives you a 2.43V change for 150A It also has an offset of Vcc/2, so when you apply 12 VDC power it will have an idle output of 6 VDC. There's a reason the DC transducers cost a bit more - you really need to amplify the output signal and remove the offset to come up with a standard process value. Or not. I've never tried the Raw Value configuration and the E3XB datasheet says something about frequency when you select this. I'd use the 0-10V range in 14 bit mode. This gives you 1 count per 1.63 mV, so you'll get about 10 counts per amp. Also take into consideration that the A/D will "chitter" a couple of counts all the time. Plus +/- 0.4% full scale error, which works out to an uncertainty of 66 counts, or 0.6 amps on a 150A full scale device. Just make sure your eyes are open before you jump into this project. Joe T.
  41. 1 point
  42. 1 point
    I'm guessing your baseline is DC transducers in the $150 each range. Those are raw sensors and you're going to have to build a circuit board for them. And come up with a dedicated 12 VDC power supply. And test each one's output with a known meter at several points to calibrate them and set up your program. But yes, they should work. Give yourself a couple of days to do it. Joe T.
  43. 1 point
    Just for clarity to everyone following this saga. The EXL-CAB295 is for the EX-A2X, NOT the EX-A1!
  44. 1 point
    This is a classic example of how a transitional being called affects things akin to my statement above: " something unexpected going on during one of those "setup" scans can affect things ". The plc deciding what is being asked and finally setting things at the end of the scan, such that only one scan totally disrupts an expected operation, is an easy trap to fall into. And we have all done it at some stage! "Why didn't that work? Hmmmmmmm....the logic looks right so it must be a sequence issue missed by the dumbkerfarfen who wrote it!" (Hey...my new word that google's never heard of!) Without knowing the rest of your program, I would be putting ALL your motor controls in the one sub, which is constantly called. Another thing that you may possibly need to take into account is that you are running the motor via modbus, which has inherent delays that must be allowed for within all your controls. Things like emergency stops, deadband/hysteresis, etc. cheers, Aus
  45. 1 point
    Everyone encounters this type of problem from time to time. Rest assured that the PLC is executing the code properly. You can troubleshoot by placing an Increment function with an unused MI at strategic places on the suspect rungs. Here is how I would go about it: First, perform a search to make sure MB 12 & MB 33 are not being used elsewhere by mistake. Second, confirm the subroutine is being called by the Main Routine. Third, place an increment function just after your MB 33 Set coil. Fourth, place another increment function (different MI) at the end of your logic thread with the MODBUS FB. Then download and go online and watch what happens. I have one more question. You addressed how MB 33 was being Reset. How about MB 12?
  46. 1 point
    I've got customers that can't grasp the concept of an All-in-one and simply refer to it as the HMI. I think the HMI Controller terminology would be something they could understand better.
  47. 1 point
    I like your way, too! It demonstrates that you can think in terms of bits, which are the foundation of all the other data types. There's a cat being skinned multiple ways somewhere.... 😁 Joe T.
  48. 1 point
    Hi all, This Topic will list items that are worth an easy find, but are not quite "pinnable" on their own. If we pin everything that is useful, it will all become one big mess on page 1 (or bigger!). I suggest that if you want something added to the list, contact myself or another mod to have them edit it into this existing list that I see as having carefully considered updating. To save space, only links will be shown, not full previews, with the Header or a Description listed before the link. Sometimes the link will take you to a particular post within a Topic that is the answer, but a full topic read will never go astray....history is useful. Just a link to the Help Centre, which perhaps many people don't know about. The link actually goes to the Vision/Samba firmware update troubleshooting page, but you can easily back out of there using links under the Help Center heading to find many other topics about all things Unitronics. https://support.unitronics.com/index.php?/selfhelp/view-article/visionsamba-firmware-upgrade-troubleshooting HSC resets DW counter after power-cut http://forum.unitronics.com/topic/6118-hsc-resets-dw-counter-to-after-power-cut/ Multi Monitor (things disappearing) Issue http://forum.unitronics.com/topic/5827-multi-monitor-issue/ Setting up EX-RC1s (particularly Joe's explanation at post 9.... 21520) http://forum.unitronics.com/topic/4165-setting-up-two-ex-rc1/?tab=comments#comment-21520 Run Multiple Instances of Visilogic etc and making good use of this ability. http://forum.unitronics.com/topic/4015-multiple-connection-live-checking-tip/ EX-A1 vs EX-A2X Connection cable differences. http://forum.unitronics.com/topic/58-ex-a1/?do=findComment&comment=26267 Trend Disappearing in various scenarios. http://forum.unitronics.com/topic/5233-v700-trend-disappearing/?do=findComment&comment=22704 Many Screen Elements makes PC do long refresh time. http://forum.unitronics.com/topic/6590-visilogic-9880-hmi-frustration/?do=findComment&comment=28338 Connections suddenly showing "No PLC is currently selected..." http://forum.unitronics.com/topic/6478-connection-problem/?do=findComment&comment=26158 Connection details storage tip related to no. 9. Store all evb details elsewhere. http://forum.unitronics.com/topic/5439-hiding-remote-locations-on-your-pc-from-crooks/?do=findComment&comment=21086 Great Subroutine advice. http://forum.unitronics.com/topic/7081-subroutines/ Intermediate Calculations Using Same Operands....great explanation from Joe for those who don't know about this. http://forum.unitronics.com/topic/7207-linearization/?do=findComment&comment=29492 Initialize & Reset might fix weird things. http://forum.unitronics.com/topic/7271-initialize-reset-might-fix-weird-things-going-on/ cheers, Aus 🙃 (mods note, Header 16 bold strong blue, link 10 bold)
  49. 1 point
    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
  50. 1 point
    This is a good suggestion. I recommend you read up on how PID works and how each parameter affects the loop. Nobody takes time to learn anymore! Read the Help topic "PID Config Struct Parameters". So are you reading temperature in whole units or decimals? You mention SP = 110, but you say you get 109.5. Please be more specific. Is your setpoint 110.0? I'm going to assume you are working with 0.1 degree resolution. Your loop is too tight for minimizing overshoot. Set Kd (Td) derivitive time = 0. You don't need it unless you anticipate upsetting the system, like opening the door on an oven or dumping cold product in. The units on Kp are 0.1% of PV, which defines when the algorithm becomes active. So initially with Kp = 1, and SP 110.0 you are activating the PID at 109.9 degrees. With Kp = 5, it starts working at 109.5 degrees. Sound familiar? Manual loop tuning 101: Start with Kp = 100 (10.0%) and Ki = 0. Then start lowering Kp until the process starts to just ring around the setpoint. If it overshoots wildly you need a bigger Kp. Measure the time between peaks. This is the natural cycle of your process. Then take your Kp value and double it. The units on Ki are seconds. Enter the time between peaks value. Let us know how it goes. Joe T.
  • Create New...