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Good day. I can't understand how the memory (Latch) is arranged and what the battery affects. The manuals are very uninformative. 1) iQ-F and iQ-R store the program in EEPROM. Without a battery, the program is not destroyed (as in previous series). Do I understand correctly? 2) In the memory settings, there is a Latch area. Registers retain their value when the power is turned off (I checked in practice), without a battery. How long will they be saved without power? 3) What changes in the operation of the Latch area if we install a battery? 4) Is the operation of the Latch area the same in iQ-F and iQ-R? 5) Thinking out loud. All registers by default work in RAM memory and when turned off, the Latch area is saved in EEPROM. Then when turned on, it restores the values ???

Hi Everyone,I have a customer that needs a CQM1H (CPU51) replaced. They purchased the processor new-old-stock from a source they found online. It arrived in the original packaging and had the safety label around the top of the unit, so it seems that it is as advertised and no need to suspect that it would have problems. I purchased secondhand, a power supply to attach to it and program it from the bench instead of in the machine. The customer also provided me with an SD card containing the project file(s) for the machine. I am able to load the project in CX-ONE (running on Win 7) just fine. My computer has a native serial port (COM1) and I built a programming cable to work with the DB9 peripheral port according to a diagram I found online.The processor powers up right away with the ERR/ALM continuously on. No other LEDs came on initially, and after a bit of playing around with communications settings, I finally landed the right protocol and my computer seemed to identify the processor correctly. I compiled the source and attempted a transfer to the PLC. I got some failed message (or maybe messages) at the end of the transfer. It did seem to send all of the binary code, it just ended with an error message that I unfortunately didn't write down or grab a screenshot.Anyway, what I have now is a PLC processor with the ERR/ALM LED on always, I've never seen it in RUN mode, and now after the programming attempt, I'm seeing the COMM LED strobing at about a .5sec frequency (with or without a cable attached to the peripheral port), AND I cannot get CX-Programmer to again acknowledge the processor anymore. I'd like to reset this back to the way it arrived to me, but can't figure out how to make that happen offline. The DIP switches don't seem to cause that effect. I should say also that the DIP switch settings are all OFF except 3 and 7.Any help is much appreciated!Thanks,John

Hi All, We have a hydraulic press that is being controlled by Siemens S5-95U PLC . Lately the S5-95U has been randomly stopping during operation thus causing the hydraulic press to stop running. However the S5-95U instantly returns to RUN status after stopping. This is the first time it has happened after a decade of service. Prior to the random stops issue, around January 2021 the S5-95U completely stopped and the program in the RAM was erased so we had to replace the PLC battery and restore the program with our backup. Strangely, the PLC battery we replaced still had 3.4VDC upon checking. What's even more baffling is that even after we replaced the PLC battery with a new one, Battery LED is still yellow although the program is still retained in the RAM. In summary, we have two concerns: 1. S5-95U randomly stops and resumes during operation ever since we were forced to replace the PLC battery and restore the program. 2. PLC battery has been replaced but the Battery LED is still yellow but the program is still retained in the RAM. I have a suspicion that the two concerns I mentioned above are somehow connected but I lack the technical expertise to diagnose. I'm hoping someone can help me figure out our issue. Worst case, I think our S5-95U needs to be replaced. Thanks,

Hi All, We have a hydraulic press that is being controlled by Siemens S5-95U PLC . Lately the S5-95U has been randomly stopping during operation thus causing the hydraulic press to stop running. However the S5-95U instantly returns to RUN status after stopping. This is the first time it has happened after a decade of service. Prior to the random stops issue, around January 2021 the S5-95U completely stopped and the program in the RAM was erased so we had to replace the PLC battery and restore the program with our backup. Strangely, the PLC battery we replaced still had 3.4VDC upon checking. What's even more baffling is that even after we replaced the PLC battery with a new one, Battery LED is still yellow although the program is still retained in the RAM. In summary, we have two concerns: 1. S5-95U randomly stops and resumes during operation ever since we were forced to replace the PLC battery and restore the program. 2. PLC battery has been replaced but the Battery LED is still yellow but the program is still retained in the RAM. I have a suspicion that the two concerns I mentioned above are somehow connected but I lack the technical expertise to diagnose. I'm hoping someone can help me figure out our issue. Worst case, I think our S5-95U needs to be replaced. Thanks,

Hi, FX-2NC-32MT PLC need to change Battery, Can you please tell me the battery model no? Which communication cable require for FX-2NC-32MT PLC upload or download program? Thanks & Regards Sohel Ahmed

I have run across a Mitsubishi FX2N with a battery light on. I have never worked with Mitsubishi before, but the manual describes changing the battery and indicates the controller must be powered down for the change. You have to beat the clock and change the battery within 20 seconds. Has anyone changed these batteries while powered? Used to do that with PLC5's but I have never dealt with this processor before.

I want some recommendations for a PLC that can hold its memory for long periods of time with no power. I have a customer that has the molds that only get used a couple of times a year and when they are not being used they sit in storage until they need them again. Currently they have a DirectLogic05 controller and what they have noticed is that when they pull these molds out of storage to use them, the program is lost and they got to download it again. They want to make it to were all they gotta do is plug and play basically for this machine. Is there a special module or a processor that can hold its program for long periods of time while it has no power on it?

Does anyone know if the Q50UDEHCPU is supplied with a battery for saving the RAM memory in case of power down? Also i read that you can put a second battery to back-up the memory stored in the Memory Card in case of power down. Is this also supplied by Mitsubishi or does it need to be ordered separately?