Flex727

I'm having a similar problem with VisiLogic version 9.8.31. Whenever I try to communicate with the PLC with a serial connection, the Modem box pops up and the connection fails.

Double click on the display background to get a pop up that allows selection of this attribute and others that apply to every element on that particular screen.

You cannot change the Data Table name via ladder, but there is no need to. If you want to store and recall your recipes in a Data Table, then make each row of the data table a separate recipe. The first column can store the name, then subsequent columns would store each of the recipe parameters. You would then use available data table functions to store or recall all the items from a row.

Just use a self-resetting delay timer, as follows: T0 T0 -|/|------( )- ------------------------ T0 -|P|-, in place of SB13

HW configuration takes just seconds. Are you referring to I/O operand labels? If so, you can export operands labels to Excel, edit it as you wish then import to another project. If it's analog I/O configuration you're talking about, then I don't know of any way to transfer to another already existing project.

It looks to me like you're confusing certain things. The Preset value you see in your ladder is set by you, the programmer, and will not change unless you check the appropriate box on download when the Preset value in the PLC is different. The Preset value in the PLC will change when, like the above, you download the program and check the appropriate box. The PLC Preset value can also change in the PLC by keyboard entry, but the change will not be visible on the screen (if the Preset value is being displayed) until the timer is next reset, either by Reset coil or by timer expiration. If the timer is running when the Preset is changed, the new Preset will not take effect until expiration of the current cycle. There is no need to restart the PLC for timer changes.

Unless I'm misunderstanding what you're trying to do, all you need to do is delete the Snap-In module and add the Expansion module in the HW Configuration, then move all the I/O to the appropriate addresses using the Edit/Replace function.

I'm not sure "one shot analog output" really has any meaning. You will need to have a thorough understanding of the electronics involved (rise and fall times, etc). If you just need a certain voltage or current output for a short period of time, use the analog output or a relay attached to a digital output and run a timer in the PLC triggered by your input. There is a very convenient "Extended Pulse" timer you can use.

Just move the MB 49 Reset to the next rung gated by the MI 1 comparison. There is no reason to try to cram too much logic into a single rung. Unitronics will not charge you by the rung. It's always better to break up outputs to have a single one for each rung to avoid large network compile problems.

Confirm you have selected the correct Com port in the VisiLogic software. If that's correct, and you are using the Unitronics cable, then the most likely problem is a driver issue.

Forcing inputs on and off during Online Test can be a bit of a pain. I wish we could force inputs with a single left click just like Memory Bits. This is another good reason to buffer your I/O. If the input is buffered, then you can insert a test MB to turn the input buffer bit on and off easily.

I think they can be obtained for about $40 each. We always struggle to have enough digital outputs and these look like an inexpensive way to add more. The caveat is that we have to be willing to endure the delays as compared to a relay attached to an I/O module (and potential reliability issues?). I should have one in hand in a couple of weeks and will play with it to see what I can make it do.

Anyone ever tried to communicate with one of these devices with Unitronics PLC? Ideally, I'd like to be able write to the relay address from the PLC using Ethernet. http://kmtronic.com/modbus-relays.html

Why not just program like a thermostat? Set a minimum temperature and open the valve when the temperature is below the minimum. Close the valve when the temperature is at or above the minimum (or the reverse - not sure what valve you're opening and closing). I would be cautious about using Pulse-Width Modulation on a water valve since you might end up with a lot of water hammer or excess wear and early failure on the valve itself.

This is not a problem with your linearization. Minus 25 is the correct output for an input of 0. If your wiring and other hardware is correct (and you have MI 0 assigned to AN 0) you should always get a minimum value of 204 at MI 0.

I totally agree with HigHTech, but I have found that if you have more than 4 or 5 screens on the Samba, you will have a big problem with memory. This is especially true if they are even moderately complex screens with a number of elements on each. I suspect that will be your number one problem with memory limitation when you move from the V350 to the Samba.

Move those operand addresses FIRST before exporting.

Yes, I just had a configuration issue (port numbers weren't addressed properly). These PLCs can definitely act as both a Master and a Slave simultaneously.

Do you have a Snap-In module attached? I've had that happen when the module is not fully engaged.

Perhaps the Unitronics developers didn't handle the error message in the most elegant manner possible, but fundamentally they are offering you two touch choices that are necessarily going to be in conflict. Clicking the "Keypad Entry" box will cause the touch to bring up the on-screen keypad to enter the ASCII data that will go into the vector starting at MI 110. The "Touch" box will allow you to use the displayed ASCII variable to perform some other action in the ladder by making the assigned MB go high when touched. These are two different functions and you can only choose one.

Yes, but also the text and diagram show a vector length of 10 starting at MI 50 and ending at MI 60. It should run from MI 50 through MI 59 or Run from MI 51 through MI 60 (or else change the vector length to 11).

I'm pretty sure that's a typo in the Help file. Perhaps someone can get Cara Bereck Levy's attention on this.

Very true, HigHTech! And thanks again for your help.

This project continues to challenge. Not only have I choked several ladder subroutines, but I ran out of transition contacts. I've never done that before with an enhanced vision PLC. It's been a real learning experience as I had to go through the program and determine if I REALLY needed that positive transition contact (e.g. for a button press, etc). Obviously for a button press to navigate to a different screen, a PT contact is absolutely necessary, but to RESET most alarm latches, it's not that important (as long as the SET RUNG follows the RESET rung, not before). I also changed my logging routine to the more sane method suggested above by HigHTech. I had to move well over a hundred MBs to a vector, but it cleaned up my program nicely and the EVENTS TRACK FB works very well for this application.

Just use binary text or binary image buttons with TOGGLE turned on, then have a ladder rung for each button with a positive transition RESETing each of the other buttons.