Micro 810 Edit Varible from LCD

It's my first time programming a PLC, any help would be appreciated.

I'm using a proximity sensor to detect an object, followed by a solenoid to spray the object. There are two timers, one to delay the spray while the piece moves into position (if necessary) and a second that adjusts spray duration.

I'd like the user to be able to adjust the times from the LCD, but it shows "no variables" under the variable screen. I tried making them local and global, no success. I'm not sure what to do.

On a side note, I used the set and reset functions to keep the input "on" while the timers execute. It works, but maybe there's a better way?

Thanks

Hello and Welcome to the Forum!!

I have never used the LCD for user input but have done it with the MicroLogix 1100. The ML1100 is a major PITA to program and even use. So if the 810 is anything like the ML1100 I would say you might want to look at doing it another way.

According to the items I have attached, the LCD on the 810 can be used for user input. Take a look at these items and see if you want to take it on.

As for using the SET and RESET for you outputs that will work. What you are really looking for is a Timer Timing Bit (TT). A bit that stays on as long as the timer is active. In RsLogix 500 or 5000 that is available but is not available in CCW. So I have posted a little program I wrote that will close my Garage Door at 11pm if I forget to close it. I shows another way to create the TT bit. You may find it helpful.

If you have any more questions please post back.

Thanks for the help. My main problem with the micro is that the software documentation is not very good. There's a lot of trial and error. Though I'm glad to know I wasn't far off on the ladder logic.

There's supposed to be a feature for the LCD where it automatically recognizes variables (starting in version 7), but this doesn't seem to work? I'll try the option you posted tonight. My company is fixated on allen bradley, so I needed a low cost option to teach myself. I'd rather use a click or some other unit, which seems to get better reviews.

Are all the micrologix units terrible, or just the 1100?

Alphite,
I think you may have misunderstood my comments about the MicroLogix. I was referring to programming the LCD for data entry. From my experience, it doesn't work as smoothly as I would like. Most of the time a cheap HMI would be a better solution for data entry than the on board LCD.

As for the Micrologix line I love them!! They are a great PLC. I started my PLC career programming Micrologix 1000 and 1100.

You mentioned that you wanted to learn AB programming. Does your company use a lot of Micro 800 PLC's? If not, I would suggest the Micrologix as the PLC to start with. The ML's use RsLogix 500 for programming (also used with SLC 500 processors) which is similar to RsLogix 5 (PLC 5) and RsLogix 5000 (Studio 5000) (ControlLogix and Compactlogix). So if you get good with RSL 500 you will be able to move into other programming Suites with much less effort. The Micro Line uses CCW (as you know) and has more in common with AD or other IEC programming suites than RSL. It is good to know the IEC type of programming but if you want to learn AB for use at work I would hold off on the CCW until you had a chance to get up to speed with the RsLogix. IMHO.

You can download a free copy of RSL 500 that will work with the Micrologix 1000 and the 1100. So if you can find a cheap 1000 or 1100 on ebay you can be leaning pretty cheap.

Hope I helped you out.

FWIW to the OP's question,

I've wondered this for quite a while and knew it was possible to edit a variable with the detachable LCD screen on the Micro 810. I tried figuring it out on multiple occasions and after some poking around today, I finally figured it out.

First things first, use the Key_Read instruction and map out the LCD screen's keys.
Then after that, use the left and right keys to count up and down.
Use the counter's variable to "select" the menu position.
Then reference the menu position with an equals statement.
Use the equals statement to allow up and down key presses to add/subtract at whatever interval you desire.
Then use DTOS - dint to string - to save that value in string data type.
Use the LCD instruction and map the saved string to line 1,2,3 or 4.

Previously when using the Micro 810 the only thing that was useful was the I/O status on the LCD. From that page, now you can press the escape key a bunch and the variables screen will pop up. Now you can scroll left/right and access a menu number or name and then use the up/down keys to change the variable.

I'm sure after messing around with the LCD controls and seeing what you're doing you'll be able to figure it out. Now I can adjust my program's delay time and reset time without making program changes. If you "retain" all variables, your values won't change on power cycle by the way.

Hope this can help somebody as I was certainly confused on multiple occasions until I figured it out. This thread may be dead, but I figured I'd post anyway.