adccommunitymod (AutomationDirect) asked a question.
Created Date: January 20,2020
Created By: ZedIDave
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I am having an issue with a BX Do-More system. I am having the output side of a rung being activated while the left side logic are not calling to activate the coils and MOVE instruction on the right side. The hardware that I have is the following: BX-DM1E CPU 1) BX-16ND3 Input Module 1) BX-12TA Output Module Firmware version – 2.6.3 This is a single cycle machine. Each cycle the operator must press the START buttons to initiate the cycle and again once again after the carriage has moved to the press area. I can operate the machine for 10-15 cycles sometimes before this rung wants to activate itself. The scenario is a follows and this only occurs on this one rung. Rung 29 is the rung with the issue. The following occurs when the issue crops up. V2000 has 9 loaded C70 is set The logic that is supposed to occur to activate these instructions are V2000=8, x14 is true (and it is at this time), C69 must be true V2000 does not get 8 moved and C69 never becomes true from the capture logic I have. I have rungs 23-28 being used to capture the logic used on rung 29. None of these latch bits are set when Rung 29 outputs activate. Rungs 30-31 are used to capture C70. These capture bits are then reset once the Left Start button is pressed to allow me to view them. I have attached a pdf of the program and the actual program file. Has anyone come across this type of issue before? Thanks
Created Date: January 20,2020
Created by: ZedIDave
I am having an issue with a BX Do-More system.
I am having the output side of a rung being activated while the left side logic are not calling to activate the coils and MOVE instruction on the right side.
The hardware that I have is the following:
BX-DM1E CPU
1) BX-16ND3 Input Module
1) BX-12TA Output Module
Firmware version – 2.6.3
This is a single cycle machine. Each cycle the operator must press the START buttons to initiate the cycle and again once again after the carriage has moved to the press area. I can operate the machine for 10-15 cycles sometimes before this rung wants to activate itself.
The scenario is a follows and this only occurs on this one rung.
Rung 29 is the rung with the issue. The following occurs when the issue crops up.
V2000 has 9 loaded
C70 is set
The logic that is supposed to occur to activate these instructions are V2000=8, x14 is true (and it is at this time), C69 must be true
V2000 does not get 8 moved and C69 never becomes true from the capture logic I have.
I have rungs 23-28 being used to capture the logic used on rung 29. None of these latch bits are set when Rung 29 outputs activate.
Rungs 30-31 are used to capture C70.
These capture bits are then reset once the Left Start button is pressed to allow me to view them.
I have attached a pdf of the program and the actual program file.
Has anyone come across this type of issue before?
Thanks
Created Date: January 20,2020
Created by: Todd Dice
My assumption is when you 're moving 8 into V2000, the other three N.O. bits of rung 29 are also true, but just for a brief moment. I'd check there first.
As a side note, your logic looks like an excellent candidate for Stage programming.
Created Date: January 20,2020
Created by: ZedIDave
Thanks for the response Todd.
That was my thought initially. That's why I put the trap bits after the rung that is getting skipped thinking it may only be active for one scan. But these trap bits are not getting set. So I am at a loss. I have contacted Tech Support and they are looking into it.
Created Date: January 20,2020
Created by: Todd Dice
You could also message BobO, as he's from Host, the maker of the BRX PLC.
Created Date: January 20,2020
Created by: Gizmobreaker
Disclaimer: I am relatively new to Do-More Designer and AD PLCs. I do have a lot of experience with Idec PLCs, though.
I have run into this, on occasion. Here ' what has worked for me.
Assuming that you don't have some single cycle turn-on of some part of your rung, I would delete the rung, save the file, close the file and Do-More Designer. Then reopen DMD and your file and enter the rung from scratch. Tempting as it may be, do not copy and paste the rung. Add new rungs before your rung 29 that set flags if any of the rung 29 coils get turned on, even the elements that are on the output side; that way you'll know if something is getting triggered that you cannot see because it's only on for 1 cycle.
I do not know why this works. It has something to do with editing the rung and some element not getting properly deleted, even though you can no longer see the element.
Created Date: January 20,2020
Created by: ZedIDave
Thanks Gizmo, I tried that on Saturday along with clearing out the PLC memory before I started to pull my hair out and I don't have much left. I have run across similar things like that in the past and did like you said and it works.
Created Date: January 20,2020
Created by: BobO
Thanks Gizmo, I tried that on Saturday along with clearing out the PLC memory before I started to pull my hair out and I don't have much left. I have run across similar things like that in the past and did like you said and it works.
If there is a simple way for us to duplicate what you think is misbehaving, we are happy to do so. We'll need a program that will exhibit the issue and a list of steps required to do so.
Created Date: January 20,2020
Created by: ControlsGuy
Another diagnostic (and occasionally therapeutic) step is to put the sequence steps in reverse order in the ladder. That way you 're guaranteed minimum one-scan step duration, and you know it can't go skipping through three or four steps in a single scan.
Created Date: January 20,2020
Created by: ZedIDave
Thanks BobO
An updated program file is attached. The only difference in this file and my first post, I changed the resetting of my trap bits to an external un-used button.
The issue has to do with the Auto Cycle that starts at rung 11
Start buttons are pressed, the Die Frame lowers
Start buttons must remain pressed while Die Frame lowers.
Die Frame is lowered
Carriage with Die Frame is pushed to press area. - Rung 20
With the Carriage at the press, press Start buttons to begin Trim Cycle. – Rung 21
When Trim Dwell is done, allow press to lower – Rung 29
When press has lowered, Carriage can be pulled from the press area.
Once Carriage has been pulled back out to the operator position, the Die Frame will open.
Once the Die Frame is open, cycle is complete.
When the issue comes up, the logic jumps from Rung 21 where I should be loading a 7 to V2000 when pressing the Start buttons to Rung 29 where 9 is loaded to V2000. The trap bits on rungs 23-28 are not getting set when this occurs. X8 is an external push button that I am using to reset the bits.
The trap bit C303 on rung 30 is getting set and 9 is being moved to V2000. However the logic to trigger this is not occurring.
Thanks
Created Date: January 20,2020
Created by: BobO
This procedure sounds dependent on the machine. That'll be a bit harder to dupe.