Capturing data in RSLogix 500

[rta53]

I think I have asked about this before but here goes:

We have a PC setup in our office that dials out to a SLC 5/04 at one of our customers. Using RSLinx and Excel we are capturing about 30 analog readings so we can log the performance of the process. The modem dials out every 45 mins. The problem is that parts of the system runs intermittently and so about half the time we only get readings for some of the process. What I am doing now is programming a bunch of MOV instructions in RSLogix 500 to capture the data. I want to do this 4 times a day so it's going to take a lot of MOV instructions. I will set up Excel to read the addresses where I have moved the data. I will also capture the time and date with each set of MOVs. For example, I want to capture F8:0 to F8:30. At 8:00AM I will MOV these values into F16:0 to F16:30. At noon I will MOV F8:0-F8:30 to F16:31-F16:60, etc.

As I said the MOVs will occur about 4 times a day and also when the process is running. At the end of the day the PC will dial-in to capture the readings in Excel and then I will clear all the words in F16 after a programmed time. Setting up the conditions for when the MOV occurs is not a problem. My question is this. Someone suggested to me that I use indirect addressing for this. I have never used indirect addressing but I understand the way it works. Will this be a good shortcut? In Excel I would set up 4 columns that would each contain 30 references to the F16 words. Is there an easier way than doing 4 sets of 30 MOVs?

 

[bwheat]

First when you move floating points to integers you are going to loose precision. If that is alright the OK. Otherwise you might want to move the data to another floating point file.
You can use the COP command. It will copy a block of registers to another block of register. Example: COP N7:1 to N10:1 length of 10 would copy N7:1 to N7:11 to N10:1 to N10:11.

 

[dash]

Depending on what kind of data and the relationship of the data a FIFO may be easier. Also there are some industrial modems (SixNet) that will allow the PLC to use a discrete output to cause the modem to call a number that is programed in one of the S registers in the modem.

Darren

 

[rta53]

First when you move floating points to integers you are going to loose precision

That was dumb on my part. I will be moving Floating Point to Floating Point. I fixed it in my post.