FIFO Array help Rslogix 5000

Hello all,

I need some guidance creating a FIFO array to display data into an HMI. The data will be the sum of jams of a conveyor section in an hour. The jams total to be display will have to be last hour jams and update every 5 mins so we can work with an array of 12 instead of 60. The total of jams (all time jams since logic was created) is already in the current rung in an add instruction. I will just have to make this value only display the last hour total only. Im open to any ideas on how to make this the most simple as possible.

Would a trend be better suited for this?


I use the FFL and FFU instruction a lot and usually have something like this.



Timer.DN
------|/|-------------------------- Timer
Timer.DN FFLControl.EN
------| |----------------|/|------- FFL
FFLControl.DN FFLControl.EN
------| |----------------|/|------- FFU


Source tag is your count

Create a dummy tag for the Dest FFU.
Then HMI tags I select the last element as the latest record to display.

First off I would not use a FIFO. I would use a Copy instruction to shift my data. If you copy Array[1] to Array[0] for length of 12 it will shift your data. The most current data will be in Array[11] and the oldest will be in Array[0]. Make your Array Length 13. This will let you copy data into Array[12] and shift it to Array[11]. Then you will display Array[0] thru Array[11] for your 12 sections of 5 mins. In essence you will be copying Array[1] thru Array[12] and pasting it in Array[0] thru Array[11]

Make sure you use one shots bits to do the math. Create a DINT named Oneshot. This gives you 32 bits for the ONS instructions.



XIC System Run [ONS] Oneshot.0 COP Total Jams to Current Jams.
XIC Timer_5M Done [ONS] Oneshot.1 SUB Total Jams - Current Jams = 5 Minute Jams. Copy Total Jams to Current Jams.
XIC Timer_5M Done [ONS] Oneshot.2 COP 5 Minute Jams into Array Jams[12] Copy Array Jams[1] To Array Jams[0] for length of 12.

XIC System Run XIO Timer_5M Done TON Timer_5M 300000 0

Make sure you put your timer in the last rung under your math.


If you don't care about the first hour after logic is installed. then you can add a rung using the AVG instruction and then Multiple The Average of the Array by 12 to get you Hour total.

CWAL61 that makes so much more sense and a lot easier. Will try it in the morning and update you with results. Again thank you so much for the brilliant idea

Note: If you go with the Average Instruction to get hour total then make sure you use a REAL for the Destination tag. This way you'll get a percentage for any hour where jams are less than 12.

Thank you sir! Yes I used the AVE instruction with the real and multiply by 12. Worked perfectly