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sokhanh

Help me with c200h-lk201

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Thank you for your reply! - The PLC seem to be ok but the connect to computer. LEDs on the I/O light correctly. Only led "Run" on the CPU and on the LK201 light. - When I try with the Host Link in the blank slot, everythis is the same - When I remove all the modules from the rack and try the Host Link in another slot, only led "run" on lk210 light, cannot connect cx-programer, on the cpu led "run" light led "error" flashing ( alarm) ( Could be incorrect I/O table)

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I have created a similar situation with my test rig. (C200H CPU01). I created an I/O table then swapped the modules around. I get the flashing ALARM light as well. I am still able to connect with the LK201 even though it is in a different slot. Only try this if you are comfortable doing it. Use a 9 Volt battery and connect the minus (-) side to pin 7 of the RS232C port of the LK201. Take the plus (+) side of the battery and briefly touch it to pin 3 of the RS232C port of the LK201. The RCV light should come ON. I did this with mine. I did this using small pieces of wire and sticking them inside the pins. - The PLC must be powered ON and the RUN light on the LK201 must be ON. - Double check your connections before touching the 9 Volts. I don't know what will happen if you select the wrong pins. - If the RCV light does NOT come ON then I would have to say that the LK201 unit is bad. Try both units. I find it unlikely that both of them are bad. - If the RCV light does come ON then you either have a bad cable, connector or connector pin.... or you are not sending data. Edited by IO_Rack

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When all else fails, introduce a little voltage.....

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Thank you! I've used 5 Volt, 9Volt and 12 volt as you suggest, but RCV doesn't come ON. Both of them could be bad!

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In my experience these units are very tough. Rarely, do I see them go bad. Nonetheless, your testing has shown us they will not respond. Do you know what happened prior to the PLC going bad? I do not wish to beat a dead Host Link unit but just for good measure, you should try each Host Link unit in the CPU Base Unit rack again, attempting to communicate with your monitoring system and with CX Programmer. Take note of the status of the XMT and ERROR lights. If either of them come ON then that is an indication it is receiving something. The manual does suggest the indicator circuit for the RCV light could be faulty. The LK201 is obsolete and is the only option for communication with these PLCs, other than the 3G2A6-LK201, in which case you'll also need the BP001 due to your OC224 module in the way. You may have a difficult time finding one. You'll probably have to search the web. There are some 'after market' repair centers and Ebay. Alternatively, you could upgrade. The physical upgrade would be very easy as you could reuse all your modules and you can get them with a Host Link port built into the PLC. The down side is, the Host Link commands may (or may not) need to be tweaked and you still need the program from your existing unit. Contact your local distributor for more information. Edited by IO_Rack

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There were 47 results today for C200H-LK201 on ebay. Here's one for $30USD. C200HLK201 at ebay.com
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PLC was running normally untill the cpu unit suddenly off then cannot turned on. It was replaced by new one, the ROM unnit was moved to new CPU. Then PLC run without connect to computer. Is there anny thing form CPU unit or ROM unit that control Lk201 function such as clock, activate signal..? Thank you!

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To the best of my knowledge... No. After all, the LK201 is the interface used for programming the PLC to begin with. To elaborate on your question... Your PLC possibly has a 'Registered I/O Table'. I guessing this because of the ALARM you got when you removed the modules. So the PLC possibly knows where it is at on the rack. But... The pre-Alpha series PLCs did not require a registered I/O table except for some 'Special I/O'. I could be wrong about the special I/O... maybe it was just to generate an ALARM when something has changed. I'll bet Jay A. knows! Anyway... my testing has proved that with a registered I/O table or not, memory module or not, I can plug the LK201 in any slot on my CPU BASE UNIT rack and connect with CX Programmer. The only other thing I can think of is, if your PLC were initiating communications to your HMI PC. In this case it would have to address the correct Host Link unit. I don't believe the CPU21 is even capable of this. The string you posted from Hyperterminal shows the PC asking the PLC for information. This is very common as Host Link is a Command > Response protocol. In either of the cases above, I believe the original programmer has made provisions for this in the ladder program. The fact the you swapped ROM modules and you appear to have a registered I/O table. It is probably writing to DM memory on power up. This is the memory that sthompson was referring to. I believe if you get a working unit and match the switch settings then you'll be OK. Good luck.

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My system is working normaly with a new Lk201, One again, Thank you so much for your help!!

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Did you get it on ebay?

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Not yet, but I 've ordered on that for spare module. Thanks you!

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You are welcome! Did you get CX Programmer to connect? You should upload the program and save it in the event you need to upgrade. The ROM module you have is good for a direct replacement as you have already learned, but you'll need the uploaded file to do a conversion in case that is necessary in the future. Thanks for responding with your solution.

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