HSCE, Resetting

[geniusintraining]

Panic and anyone else that cares...

http://www.plctalk.net/qanda/showthread.php?t=24960

This is the history that this thread comes from...

I think the only problem is the counter is reseting...by it self, with no res input, any ideas of what would cause this?...

 

[panic mode]

thanks for the link, i don't think i saw it before...

I haven't seen any proof or confirmation yet that disabling
counter reset logic still results in random counter resets.

one of earlier posts says that 'problem started happening'
indicating that it was working for some time without issues
but the thread you linked to is only few days old so this
can't be true. maybe occurance of unwanted errors just happened
to be lower or masked by other problems (we had a long weekend
here too so this couldn't be running that much).

things is saw in sample logic bug me a bit too and make me
wonder if everything else is sound there (haven't seen whole
plc program yet either)

for example i'm not sure why reset of a high speed counter card
in this case has to be variable (anything less than a second)!?
if long reset is required for example to trigger that relay output,
then make it at least repeatable. short reset pulses will not
even move realy becasue of slow relay response (it's mechanical device).

if reset has to be done this way i would like to see at least
a seal with T4:49/TT bit around T4:50/DN bit in rung 4 to keep
T4:49 timer running every time it's triggered until it's done timing.

I checked the counter card configuration (content of N9 file) and
it is usable, but I would suggest reseting N9:1/11 (change counter mode
to "Pulse count with internal direction") and changing reset mode to
Soft reset (set N9:1/7 and clear N9:1/6).

This way counter will only receive pulses from that photoeye,
everything else (other external inputs like reset, channel B etc.) will be
ignored including possible erroneous pulses they might introduce
if subject to noise or faulty wiring. (not shielded wiring to
high speed counter card is also faulty wiring!).

Since N9:1/3 is zero, it will only count up. Card itself should be quite
imune to noise (I've been using HSCE2 most of the time, don't even remember
last HSCE1...), it's the wiring that requires scrutiny.

Reseting can now be done on one shot by pulsing soft reset bit
(note that i said one shot pulse and not anything longer).
This makes it easier to catch unwanted resets, if reset ever happens
(check if I:e.0/12 is high) when PLC program didn't request it, set the
alarm bit.

Also set another alarm bit if I:e.0/13 (overflow) is ever set.

Next thing, I would evaluate those two inputs used to reset counter.
Do they maybe come randomly on (are we really sure there are no false
triggers? how do we check for that?)

may reset not be with you...

 

[controlled]

for example i'm not sure why reset of a high speed counter card
in this case has to be variable (anything less than a second)!?

I added the timer to the reset input for troubleshooting only. I wanted to see if in fact the reset input was causing the counter to reset.....That wasn't the problem, counter was resetting on its own.

Next thing, I would evaluate those two inputs used to reset counter.
Do they maybe come randomly on (are we really sure there are no false
triggers? how do we check for that?)

Again that timer is for troubleshooting only. I wanted to make sure the counter wasnt getting reset by the limit switches attached to these inputs possible becoming true from vibration......Counter still resets on its own

 

[TimWilborne]

Can you post your Rs500 file so I can take a look at it? I have a hard time fumbling through a PDF file. Need my cross references and data files

 

[controlled]

see attached

 

[controlled]

password is 1504

 

[panic mode]

if you have another hardware (hsce, rack and cpu) you can try it and rule out faulty plc. if that doesn't help, good luck and read my previous post.

 

[controlled]

Thanks panic,
unfortunately i dont have any other hardware.
I've read all your previous posts but they aren't really that helpful

 

[controlled]

Ive been monitoring the logic over the last few hours. I've noticed that when my count hold bit is energized (mo:11.1/2) the counter resets. I thought that this bit only held the count when energized not resetting it. Was I mistaken, or is there another configuration I have to look at.

 

[TimWilborne]

Actually Panics post are always very helpful. Especially when it comes to the HSCE. He is very good at them but won't suggest you do something but once. If you ignore it then...

If it's just a counter then what is the problem to set limits
to something bigger such a +/-1000000?
Also if it has only single channel input, how do you reset it anyway? If you have removed everything that could reset it
from code, then it must be either rollover or the wrong
wiring (either on used or on remaining channels).

Read page 6-2 of THIS manual. Mainly the fact that this example resets at 30,000. I was looking for code to do with the reset and realized this example has not ladder for the reset.

Go on to page 6-5 and look at the bottom. M0:3.34 is where you put your limits that Panic was talking about. This one has 30,000 in it, the same value it reset at. Since you say 3000 is the maximum your count would be I would set it around 10,000 and let us know what happens

I mainly use Controllogix and Micrologix in AB. I have never actually used the HSCE but understand the principle of it. I have heard these can be tempermental at times. This could cause an erratic reset

 

[controlled]

Sorry, I did not mean that Panic doesnt know what he is talking about, but his responses weren't helping me with my problem (although I know he was trying)

 

[TimWilborne]

What about the limits we are asking you to try. Are you going to try them?

 

[controlled]

I think that address m0:11.34 is either the maximum count (rollover count) or the count that the module is reset to upon a reset condition depending on how the module is configured. My module is set as a linear counter, so mo:11.34 is the reset value that I have set as 0, which is what i want the count to reset to when a reset condition occurs.

 

[TimWilborne]

Cancel this one, I thought you were using a ring counter

 

[controlled]

are you sure the sensors are setup and working ok? is there a chance they get triggered by accident (flying debree, dust, contact with something etc.)? Are they limitswitches or photoeyes

They are limit switches, The timer that I have is for the exact reason that panic is asking about. The input has to true for a minumum if 1 sec. in order for a reset to happen.

what is O:9/5 used for? it is labeled "reset counter card" and this output is controlled by few inputs and cascade of timers. also this is a relay output. if you need to resed PLC counter, why not reset it internaly? your OX8 card is relay output too, i wouldn't trust relay contact in anything high speed even if it's just reseting.

As I stated at the beginning of this post, I was at first using a soft reset, but changed it to a relay output reset to see if it was a cinfiguration error causing the reset.