MicroLogix 1100 String indexing

Guys I know this has been talked about but I couldn't find it. I need to do a bunch of ASCII read and writes in a 1100. It doesn't support indirect or indexed addressing or STrings. So how do I do a work around on it?

I an sending a request and expecting a reply. I have about 30 to send so I need to don't really want to AWA and 30 ARD in this program. I also have to do string parsing so it is going to be ugly at best. Any ideas?

JeffKiper said:

So how do I do a work around on it?

Any ideas?

Click to expand...

Use a different PLC.



OK, more seriously, I think you are going to have to take a brute force approach.

One thing you could do for common operations such as parsing is to program the common operations in a subroutine that uses an intermediate tag. Then copy the string to the intermediate tag, call the subroutine, then copy intermediate results to final locations.

Scary when 2 people think so close. I just pasted 30 "SOR EQU N7:9 1 COP #ST10:1 #ST10:0 1 EOR " with an index of 1 on the EQU and ST10:x
I have a sub just for parsing. I added a little small 3 rungs that will verify if the string contains a Floating point. I then make that string into 2 INTs then to a Floating point.

Nothing about ASCII is pretty in a PLC. I guess that is why they are paying me to do it.

I will drop a copy of it in this thread after it is a little more polished.

Jeff

I don't know if you know this trick or not, if you do then never mind.


Take your SOR EQU N7:9 1 COP #ST10:1 #ST10:0 1 EOR and put it on the first row of an Excel spread sheet, one instruction or address per cell. On the second row put SOR EQU N7:9 2 COP #ST10:2 #ST10:0 1 EOR. Now highlight both rows, then hover over the lower right corner until your cursor changes to a + symbol. Click-drag down to row 30. Excel will fill down, automatically indexing the compare value and source address. Now copy it all out to a text editor such as notepad, delete the carriage returns and then copy and paste the lot into Logix 500. Presto, 30 nearly instant rungs.

Yes sir that is how I do most of my duplicate logic.
I use open office so highlighting both doesn't always work so I use CONCATENATE a lot I did a couple of robot communication jobs from a CLX. Before the guys got their program even talked about I gave them a I/O sheet copied from a UDT and Modifed in Open Office.
They asked how I did it so fast. I told them I am to lazy to work hard I work smart that leaves more time to play with my kids.