Need help to replace a FX2c-96MT that is erratic with spare, but...

[androbus]

We have a couple Mitsubishi FX2c-96MT 's running a Laser engraver and one of them appears to have a faulty card or connections on the card. we picked up a couple spares one is a FX2C-96MT and the other is FX2c-96MT-ess. Is there really a difference between these? I see on the old PLC the middle card says ess on it already? we need to "harvest" the current plc program before swapping into the new unit. we picked up one of the cheapie pc connection kits which doesn't look like it is right and don't want to connect it and burn something out. IT has a rs232 on one end than a male 25-pin connector with a second cord that goes from female 25-pin to the mini-DIN connector. Neither of the FX2c-96MT plc's have a mini-din connection as i read online everywhere. there is a 25-pin connector on the top next to the FX2c-96MT label. is this the programming port? I would have assumed the programming port would either be the one covered up by the battery cover or the little one on the end with a 3/8 x 1" cover. I am assuming thae, with no instructions for much of anything. Thanks for all and any help in this matter t we should be able to use an older laptop running winXP for this? i downloaded GX developer and will install it on the xp laptop as soon as we are able to be sure of a cable that will be safe and not damage anything. If this cable we purchased will not work, could someone send a link for instructions to fabricate one? I see several in a gogle search, but they are all different and we want to make sure we do this safely as the program on the PLC is apparently NOT backed up anywhere, and the people who set it up years ago are long gon Paul

[Ron_S]

That model of PLC is very old now - long since defunct. I am suprised you could source one. (is it second hand?) But as to your main question - yes the 25 pin socket is the programming port and XP is the best way to use GX dev. The normal course would be to get the old program out of the FX2 then convert it to an FX3. download it to that, then change the PLc's wire for wire Edited August 28, 2015 by Ron_S

[Crossbow]

They are different PLCs. One model is sinking outputs, the other is sourcing. That's why the -ESS on the end of the part number. Won't work as a direct replacement. And the programming port is the 25 pin plug. Not the extension bus connector on the right end. The adapter cable you got from 25 pin to round is for using the cable with the new PLCs which use the round plug. Manuals are freely available all over the Internet on this product. You should really consider getting in contact with a local distributor and replacing it with a newer PLC. Those are well over 10 years obsolete.

[androbus]

That is unfortunate as we had understood when we ordered we weere getting two non ESS PLC's the ESS oner was actually more expensive, but he ended up sending that instead?? Do you know what the actual differences are? we have been having trouble with the center board, so simply swapped the replacement into the damaged PLC and the machine is back up running. we were going to do the same with the other laser-bank next week, but only if the board is the same. Hopefully the ESS part is on the program board of the lower board instead of the center one, and not it being a totally different device. please let me know if you have any knowledge about this. Regarding replacing/upgrading the PLC's , it's not going to happen, so we need to just keep it plodding along as it is. the company needs this machine working, but i don't see them going through the expense of upgrading as the machine is a one-off prototype and the designer/builders are NLA!

[kaare_t]

If I understand you correctly, you have opened up the unit, and simply exchanged the upper (first horizontal flat) electronic board?? This will definetively work. What Crossbow is talking about is that the inputs are either sink (PNP Positive-Negative-Positive) or source (NPN - Negative-Positive-Negative) logic. If you exchange these in either direction you will have to rewire the entire machine to handle the new logic. To explain a bit further; Sink = Negatively terminated inside the PLC -> The sensor sends a positive DC signal into the PLC, which then are terminated inside the PLC. Source = Positively terminated inside the PLC -> The PLC sends a positive signal through the input, which in turn is terminated in the sensor when the sensor triggers. Also remember that exchanging boards without the correct equipment could damage the board in hand, or other boards inside the unit. I do generally not recommend this, but as a last effort solution it makes sense, since there is no guarantee valid on the units, and doing so is your "last chance", then why not do it... But consider to upgrade the PLCs, the next time a board fails on one of the two units (which are ancient), you may have a failed input board (with the sink/source problem), or a different board holding the PLC memory (and you've already stated that there is no backup of the PLC program)... If you need to upgrade the PLCs, your best shot is definetively to contact a supplier BEFORE the units go down. When (re)programming any equipment it's a lot easier to see how the machine works when doing that actual job. In addition they might be able to simply read out, convert and do a little modification to be able to use brand new units on the same machine. You already said that it is critical that this machine is working, so I really cannot see why management is not interested in upgrading these to main components in such a machine. It's pretty ease to do the job as long as the machine is performing it's regulare cycle, and A LOT worse to do the job AFTER the machine has stopped!

[Inntele]

Don't sure that it will be applicable for FX2C PLC, However... Regarding to asian models of FX2N, one man has shared with info, that there is a wire jumper on the board, the position of which defines input logic. The jumper references input circuits to the minus or to the plus of 24VDC power supply and its resoldering allow to change logic from 'source' to 'sinc'.

[Crossbow]

The company needs the machine working yet won't put money into a current PLC which wouldn't cost much more than the spares you just bought. This is so typical yet infuriating to hear, though I deal with it every week. It's mission critical equipment and when it's down we lose money but the hell with maintaining it. Heard it a thousand times. If a truck needed tires, would they not invest the money? Or the roof leaked? Your business is relying on a PLC that is 30 years old and has extremely limited support. But a simple replacement PLC and software (or even a distributor to help with it) could make it ready for the next 10-15 years. And the process to convert it is so dang simple. Some companies need to think about their priorities better. Rant over, sorry. I am just so sick of hearing 'we can't afford a PLC, so band-aid it and pray...'