Outputs Y4-Y10 Not Outputting

[peplow 0]

Hi all, got a bit of an odd problem. Ive rigged my PLC (FX2N-80MT-ESS/UL) so that when it sees a certain button conbination, it turns on all the outputs. Now this all works fine in the sense that all the LED's on the PLC come one, but for some reason the block of outputs Y4-Y10 do not output any voltage. Every other light, output does output so im suspecting its purely a problem with that block of outputs. However is there individual block of circuit for every 4 outputs of is it all on one board and is it easy to check the condition of the board(s) if necessary? Thanks in advance Mitch

[Gambit 326]

Check the +V1 connection FX2N_Lay_out.pdf Edited 14 Aug 2007 by Gambit

[peplow 0]

Allready checked all the voltage terminals, +24V on all of them Regards Mitch

[BobLfoot 302]

I am not that familiar with FX2N and it's been a 1/2 dozen years since I connected to a mitsi, but one question does come to mind. How did you program your special button combo to fire the outputs. Any change you have multiple Y4 coils and the button triggered one is scanned before the regular one. This can cause an oscillation state and the lower current LED will light but the output develops no voltage. Something worth checking anyway. If you can "borrow" another FX2N I'd pull a swap out and see if the problem persists.

[Crossbow 295]

I would be thinking hardware problem on the board, and Mitsubishi doesn't release the board schematics, they take them back for repair. But Y4-Y10 is 5 outputs, not 4, and the group would be Y4-Y7. So if Y10 is not working, I would really tend to think someone switched too much current and burned up the transistors on the outputs.

[Gambit 326]

Just to make sure it's not a programming error. Clear the PLC program and just force the output.

[BobLfoot 302]

As usual CB you've hit the nail on the head. I couldn't remember if Y8 esited or not.

[Paul Ked 0]

Also check that you have only used --(Y4)-| to --(Y10)-| once in your program. I'm pretty sure that if you have used the 'out' instruction more than once on a physical output then the light does come on (If the last instance of the instruction is requiring it to do so) without physically turning on the internal relay or transistor. Best Regards Paul Ked Edited 15 Aug 2007 by Paul Ked

[Crossbow 295]

Paul... Nope... The light (and the output) will be controlled by the output coil closest to the end of the program (last one processed). It will not light the lamp unless the output is physically on as well.

[BobLfoot 302]

Cross - Does the Mitsi use the standard hardware construct. By this I mean 1 opto coupler to drive LED and a 2nd opto to drive the output coil or transistor. With this construct the coil or opto for the coil can fail but the led still function.

[Crossbow 295]

I have no idea.... never seen hardware schematics on the boards... As I said earlier, Mitsu doesn't release those, so I have no idea what the board design is...

[BobLfoot 302]

Just thought I'd ask.

[Paul Ked 0]

Crossbow. I'm sorry, but if you drive the output ON and then, later in the program, drive it OFF, the light will flicker. The rate at which it flickers depends on the amount of instructions in between. I've just tried this on an FX1s and with one instruction between outputs the flicker is random. With 500 between it is so fast that it looks as if the light is ON. The relay, however, remains OFF. You obviously took a guess at this one Regards Paul Ked

[panic mode 246]

now that's answer of the guy who knows how to mess things up and confuse maintenance guys...

[Crossbow 295]

I most certainly did NOT guess at this! I was going by what I was told by technical support, and the way just about every PLC on the planet operates on logic. The process is always the same. Read the inputs, run the program, update the outputs. That's the way the A is, that's the way the Q is... Perhaps the FX1S is doing some form of automatic update, or it's using interrupt processing or IMIO refreshes. But I've never been able to get it to flash as you say... I'll go try again one of these days when I get to see my office again....

[Paul Ked 0]

Modern processor technology may prohibit such actions but, as a matter of fact, how foolproof is modern technology? As people like us in the field have to 'de-bug' our office written programs when on site, so do the people writing the software for the PLC's internal workings--- (just look at RSLinks!). Logic dictates that all is well when, in fact, it can jump up and bite you in the bum due to 'human factor' or 'ignorance factor' whoever writes it...! BTW, Peplow has a problem with Y4-Y10 not outputting. I am merely offering a possible answer to his query and do not want to start a war over the internal workings of a small bit of kit! Have you found the solution peplow? Best regards to all in the forum, I hope I haven’t offended anyone, Paul Ked

[WKla 0]

This is what it happen to me when I've just started programming. Even if the programming manual says that the output is refreshed at the end of the program, if the output is used twice, the led will flicker and the relay output will remain off.

[Crossbow 295]

Well then I stand corrected. I don't have the means right now on the road to verify it. But then again, in no uncertain terms it does state NOT to use the same address twice, and typically it would be frowned upon as standard programming practice unless only one condition is executing, such as in subroutines or jump instructions. So it shouldn't be done to start with... Oh well...

[peplow 0]

Sorry i havent replied earlier, been on holiday. I took the PLC out and wired it up with just power and a single switch to check every input and output after i cleared the programme and the block still did not work so i sent it for repair and its now ok so it looks like it was a hardware fault internally. Cheers for all the replies, didnt mean to start world war 3 though

[Paul Ked 0]

Glad you've sorted it. That wasn't a war, just a bit of friendly banter As Crossbow says, it is NOT a good idea to output to the same address more than once. Best Regards Paul Ked

[peplow 0]

Cheers for the help Got another annoying problem now but its programme wise this time which ive asked about before. Initially i wanted to bring every output on via a button which i managed by using the following command line: FMOV HFFFF K4Y000 K3 But now i only want to bring outputs Y000-Y020 on and im having trouble getting my head around the correct command line. im taking it that the above line works as follows: Move the hex word value 'FFFF' out to a group of 4x'K'4 starting out at Y000 x 3? So that gave me 4x4x3 which is 48 but because its only 40 output it simply ignored the other 8? am i correct in thinking this and is there an easy way to do it, say via decimal rather than hex to simply signify i want high outputs from Y000-Y020 Regards Mitch Well ive managed to do it via the same command line but using the values: FMOV HFFFF K1Y000 K5 This gives me full output on 4x'K'1x5 = 20 out Im up on how to use and convert hex to decimal and ocatal and back etc and im fine on PLC's for the most part and as simple as this must be, im having trouble seeing it clearly in how to give the correct initial word value to bring on just the outputs you want? Regards Mitch

[Paul Ked 0]

This instruction is explained here http://forums.mrplc.com/index.php?autocom=downloads&showfile=508 I would STRONGLY advise against using this for your lamptest though, unless this is the way you want to control ALL off your outputs (see addressing more than once above ) Just to test outputs on, say, a reclaimed PLC you only need FMOV K15 K1Y0 K* (where * is the number of outputs (in blocks of 4)) Best Regards Paul Ked Edited 20 Aug 2007 by Paul Ked

[peplow 0]

Cheers Paul Ked, it clicked in my head last night as i was driving home, what a dumb booty i am. Now i look at it, its hardly the biggest task to work out, suppose thats what you get for having 2 hours sleep Cheers for the help, always appreciated Regards Mitch