SLC 5/02 project

Hello, could anyone give me some ideas on programming a application into a SLC 5/02. I have a project where I need to show how many times a fault has ocuured on a leak test in different time frames. It has a touchscreen that I am going to display the value on. I know how to just show the accumlative value , but the problem is I would like to show the history. Like how many times a condition has occured in the last 1 hour, 4 hours, 8 hours, etc. Is this even possible to do? It seems like it would be hard to do without every alarm starting a differnt timer. I do not want to use any other hardware, just PLC and touchscreen, and I just need advice on the PLC programming part. Thanks in advance and hope the explanation is clear enough.

you can pull the times with the status bits, I beleieve there is an example under downloads for real time clock then when a fault occurs record tose status bits into a data area.

s:37 clock calender year
s:38 month
s:39day
s:40 hours
s:41 for min
s:42 for seconds
most plc based faults will also record on an S value

under status files section B:3 SLC 500 instruction set manual

These status bits are not available in the 5/02. Highest status word is S:32

good catch Ken I had forgotten to check that. I wonder if he can communicate the times via his touchscreen?

Joe,

It can be done, but on the SLC 5/02 it will take some ingenuity. One way is to set up a "Master Clock". The Master Clock is made up of a 1-second timer and cascaded counters for minutes and hours.

Once the clock is up and running, it will time up to some maximum time period (for example 8 hours, selected by you), before resetting to 0.

Now that you have a master time reference, create history file locations for each alarm type, and under each type you have locations for each time period.

Leak Test Alarms in Last 1 Hour = location N7:0
Leak Test Alarms in Last 4 Hours = location N7:1
Leak Test Alarms in Last 8 Hours = location N7:2

Then you add logic so that each time an alarm occurs, a "1" is ADDED to a specific history file. Using comparison instructions and the ADD function, you add a "1" to the alarm count in the proper time category (for example: 1 hour, 4 hours, 8 hours).

Now your touch screen needs to be programmed to look at the various historical data files and display the number of alarms for each category.

ZIP your SLC 5/02 program and post it here. Perhaps I can make some suggestions about how to modify it.

Joe,

To expand and improve on my earlier post, here are some modifications.
Leak Test Alarms in Last 1 Hour = location N7:0
Leak Test Alarms in Last 5 Hours: Hour 2 = location N7:1
Leak Test Alarms in Last 5 Hours: Hour 3 = location N7:2
Leak Test Alarms in Last 5 Hours: Hour 4 = location N7:3
Leak Test Alarms in Last 5 Hours: Hour 5 = location N7:4
Leak Test Alarms in Last 9 Hours: Hour 6 = location N7:5
Leak Test Alarms in Last 9 Hours: Hour 7 = location N7:6
Leak Test Alarms in Last 9 Hours: Hour 8 = location N7:7
Leak Test Alarms in Last 9 Hours: Hour 9 = location N7:8

Then add logic so that each time an alarm occurs, a "1" is ADDED to a specific history file. Using the ADD function, you add a "1" to the alarm count in the 1-hour time category (N7:0). When the master clock reaches 1 hour, all N7 locations are rolled up by 1. N7:7 moves to N7:8, then N7:6 moves to N7:7, and so on until N7:0 is moved to N7:1. Then N7:0 is reset to 0 and a new 1-hour period starts.

At any time, the number of alarms for each category can be found:
Leak Test Alarms for Past Hour = N7:0
Leak Test Alarms for Past 5 Hours = sum of N7:0 through N7:4
Leak Test Alarms for Past 9 Hours = sum of N7:0 through N7:8