My S5 tripped - ZYK fault

[presario2100]

I have a rewinding mahine with the S5-135U, CPU928 system. Every time when the rewinding length up to 20K meter, the PLC will tripped, below 20K no problem. By looking the ISTACK in Step5, show ZYK fault. ZYK is mean CYCLE TIME EXCEEDED Did anyone know what is the reason of ZYK fault?

[Moggie]

Can you post a copy of the IStack and BStack?

[presario2100]

I'd attached IStack & BStack files, pls check it out. Actually, what's the right procedure to check the IStack & BStack when the PLC tripped? If u need any further more infomation, let me know. Thanks!

[Moggie]

The BStack indicates that the fault is possibly with FB6 and/or DB4. As everything is ok below 20K I would guess the problem is with DB4? Please see attachments for description of the IStack Zyk.pdfIstack.pdf

[presario2100]

I attached the program for you, maybe u can get some clue from the program. really thanks. DB_4.pdfFB_6.pdfOB_1.pdf Edited August 12, 2008 by presario2100

[Groo]

I can see one possible continuous loop which would cause a ZYK error. Around thye break point between page 1 and page 2 of the PDF file, after M005 label, the program can loop back to M003, there is no safety here, if the condition to enable the program to continue is not met, the program will continuously loop. Unfortunately the FB and the DB are uploaded from the PLC, which means no comments and default KH format for all data words. From M003, it increments DW11 by 4 and DW19 by 1. If DW19 is greater than 15, then it changes DW11 to 0 and DW19 to 1. From M005 he ensures the high byte of FW236 is zero then loads DW19 into FW236 (first part was uinecessary), he then loads 1 into the accumulator and the DO FW236, SLW 0 shifts the '1' left by whatever number is in FW236 (between 1 and 15 as per DW19). He then loads FW246 and AND's it to the '1' that was shifted. In other words, he is looking for the first bit that is set. If there is none then the program will continuously loop. I do notice that he starts with a 1, then shifts imediately, which means he would never check bit 0. Edited August 14, 2008 by Groo

[presario2100]

Is it this is the reason to cause my machine cannot running over 20K meter and trip the PLC? How to correct this continuously loop problem? When the machine tension is ON and machine running, then the length meter will start accumulate. When we stop the machine, Off tension, the actual length meter will still remain on the screen, but after we ON the tension again, the length meter will reset to zero, this is the normal operation. Which bit is the length meter bit inside the program? Which FB is control the second time tension ON, then asking reset the length to zero? Because I have a simple idea to let the machine running over 20K meter. The idea is to add a new DI (length reset button), then reset the length before 20K and mark it down in a paper, after add up the record then will be the total length meter. Is it possible to do it? PB10: I6.2 = Tension OFF button, 0=OFF (NC) I6.3 = Tension ON button I6.4 = Stop running button, 0=Stop (NC) I6.5 = Start running button Q5.1 = Tension ON indicator lamp Q5.2 = Start running indicator lamp Attached you can find the machine program. If need any further information, let me know. Thanks. TOPMETST.zip Edited August 15, 2008 by presario2100

[Groo]

Sorry, I don't possess a copy of S5 any more. I did notice another possible loop further down the block as well.

[presario2100]

Someone can help ?

[presario2100]

I had found some related programs inside the program file, just need some explaination for these programs. The length value was taken from the main motor speed feedback signal (pulse generator). The PG connect to a Interbus analog counter module. (Wiring.pdf) As I mentioned before, when we ON the tension during machine stop, the length will reset to zero. (see PB10-Segment70.pdf) This reset bit send to PB11-Segment10.pdf, FB69.pdf also use for length calculation. Anyone can explain these PB11 and FB69 programs? Wiring.pdf PB10_Segment70.pdf PB11_Segment10.pdf FB_69.pdf