another red lion g3 question

[504bloke]

the button tag, what is that? is that your actual tagname or does that just reference the actual button? I guess what I am asking is do I need to put my tagname in place "button"...

Button is a tag (BIT) in the plc, in this case on an ab it would be B3:0/0

Sorry, forgot to add that little detail.

 

[Gil47]

Can I make a suggestion here
Take the rung with the Unlatch currently rung 2 and make it rung 0 thereby moving current rungs 0 and 1 down to rungs 1 and 2
Then see if this changes the way it operates
I feel its worth a try.

My reason is you say the timer goes to 0 then keeps running, this says it saw the button push but some other info turned it back on.
This tells me you may have missed the timing issues involved with the bit box's you are using, in relation to the program scan, if the On and OFF message arrive a the PLC almost at the same time.

Look at Ron Beauforts YOUTUBE Video's and you may see what I am referring to.

 

[diat150]

Button is a tag (BIT) in the plc, in this case on an ab it would be B3:0/0

Sorry, forgot to add that little detail.

thanks, your suggestion worked beautifully. I hope red lion adds this feature later on.

 

[mjoubert]

Hey Guys.... i've used this in my programs and it works. Create an internal tag linked to the touch button and make it a toggle. Use the trigger function active on to switch the PLC bit on at 0ms Use the 2nd trigger function to reset the PLC bit after the time you require.

..... simple as that

 

[theDave2]

For slow comms like this, why not set the bit in the HMI, then reset the bit at the end of the PLC Scan?

If fact, this is the type I ever use, slow or fast. However, I reset the bit after seeing it ON, as some plc's will update bits in the middle of a scan.


I don't use 'momentary' (press:set, release:reset) PB's nor do I use what some call 'latching' (press once to set, press again to reset) pb's.

Both of the above kinds have 'gotchas' and other drawbacks as the OP has found out.

Dave

 

[CowDung]

I agree with the set from the HMI, unset from the PLC method.

It always seemed to me that trying to estimate time durations on push buttons would end up causing problems at some point...

 

[burnerman]

I'm in the process of doing my first project with a G306A and a Mitsubishi Fx-3. I was going to set up my HMI buttons as momentary and map them to single M bits in the plc.

Having read this thread I have had a change of heart and have decided on the following strategy:


For each button, set up 2 flag tags in the Red Lion, e.g. Start_pb_on & Start_pb_off; map these to 2 plc bits, e.g. M1 & M2 respectively.

Draw the button (or object to use as the button) on the relevant page and in the object properties, on the Action tab, set the Action Mode: Operation to "User Defined". In the Action Details, On Pressed: enter "Set(Start_pb_on,1) "

In the data tags set up, for the flag tag Start_pb_off, on the Trigger tab: set Trigger One, Trigger Mode to "Active On" and in the Action: box enter "Set(Start_pb_on,0)

In the plc program, at the top of the program,have a normally open contact of M1 energise a coil of M2. Use M2 in the rest of the program as the pushbutton contact.


I haven't tried this yet but can't see any reason why it should not work. Can anyone see any flaws in this method or do you have any better, tried and tested methods?

 

[504bloke]

Can anyone see any flaws

You had to ask

I'm in the process of doing my first project with a G306A and a Mitsubishi Fx-3.

The PLC

 

[theDave2]

...


For each button, set up 2 flag tags in the Red Lion, e.g. Start_pb_on & Start_pb_off; map these to 2 plc bits, e.g. M1 & M2 respectively.
...

I'm not sure why you are using two bits. Nor am I understanding what the HMI does with the 'Start_pb_off'.

Never the less, please see the attached picture showing how I do it.

 

[burnerman]

I'm not sure why you are using two bits. Nor am I understanding what the HMI does with the 'Start_pb_off'.

Never the less, please see the attached picture showing how I do it.

Maybe I should have explained that the Start_pb_on tag will be configured as write only and the Start_pb_off tag will be configured as a read only.

This is just for my simple way of thinking so that I know that the full loop is carried out:
1. When button pressed Start_pb_on tag is set
2. HMI writes Start_pb_on bit to plc turning on M1
3. plc turns on M2 from M1
4. HMI reads that M2 is now on and turns on Start_pb_off tag
5. The trigger on the Start_pb_off tag resets the Start_pb_on tag

I wasn't confident about only using 1 tag/bit in case there was some way that the HMI will reset its own bit without the plc picking up the change.


504bloke:
Thanks for filling me with confidence!!

Any particular reason for the dig at the Fx-3 or is it just a personal dislike?

 

[504bloke]

Any particular reason for the dig at the Fx-3 or is it just a personal dislike?

I have nothing against the fx3, or the fx2 or 1 or A1 series....

And GX is such a wonderful piece of software

 

[CowDung]

I think that his M1 bit corresponds to your HMI_PB, and his M2 is your PLC_Coil. The difference is that he uses the G3 to unlatch his bit instead of doing it in the PLC.

Personally, I think that it's cleaner to do the unlatch in the PLC...

 

[burnerman]

I have nothing against the fx3, or the fx2 or 1 or A1 series....

And GX is such a wonderful piece of software

Didn't you know, sarcasm is the lowest form of wit!!

I take it that Mitsubishi just isn't your cup of tea. Anyway, for me, it's horses for courses; for this application(which isn't particularly complex) the Fx-3 won on price and compact size.

I would be interested, though, if there are any technical problems you've had with Mitsis.

 

[504bloke]

Didn't you know, sarcasm is the lowest form of wit!!

I take it that Mitsubishi just isn't your cup of tea. Anyway, for me, it's horses for courses; for this application(which isn't particularly complex) the Fx-3 won on price and compact size.

I would be interested, though, if there are any technical problems you've had with Mitsis.

Price is sometimes good, although the S7 1200 is very well priced and really nice

Siemens 1200 TIA software is a little slow but a million times better than GX

Nothing technical other than after AB, Siemens, Moeller, Omron i find Mitsi well down my preffered list, i did have a customer who spec'd the FX2N's but i have managed to get rid of him