Well, it looks like that theory has been debunked - it turns out that INH is not as exciting as we thought.
Can you provide the complete model number of the PLC? What colors do all LEDs on the processor indicate? By the way, Omron relays in the output modules are durable and have a very low failure rate when used correctly.
The PLC in use is the CJ1M-CPU11 model with power input from a PD022 module. I have removed all input modules, leaving only the OC211 module connected. After clearing the memory, I have initiated a new program with coils designed to activate with the power supply. The Run LED is displaying green, while no other LEDs are illuminated on the CPU. The LEDs on the output module are showing yellow. Despite this, there is no clicking sound and no voltage detected between Com and any of the outputs. I am starting to suspect that the CPU may be damaged, but I am puzzled as to why the LEDs are functioning while the coils remain inactive.
I may be mistaken, but when testing from COM to the output, make sure you are connecting the test leads to points with different potentials. You require a variance in potential to accurately measure voltage. Instead of connecting one tester lead to the COM terminal, try connecting it to the other side of the control transformer or power supply. Refer to the diagram below for clarification.
- 06-09-2024
- Bering C Sparky
Apologies for any confusion – the Com is connected to the positive terminal, and I have been conducting tests by switching between the negative and output terminals in search of a 24v reading.
alphatargets stated that they were not clear in their previous communication, apologizing for any confusion. They mentioned testing the Com wired to the +ve and testing between -ve and the output terminals in search of 24v. They inquired about the reference Jxx Ch1 and expressed confusion about terminal designations, not being familiar with Omron. However, they believed there must be a logical explanation for the situation. They suggested activating a few outputs and checking them from Com + to the activated output terminals as a troubleshooting step, hoping to address a suspicion they had.
- 06-09-2024
- Bering C Sparky
There is no voltage or continuity between com and the outputs. I had a question about the Jxx address, but it turns out that was not the issue so I removed it. To clarify, based on your provided diagram, the Com on the output module is connected to 24v. I am conducting tests between 0v and outputs A0 to A7 as well as B0 to B7.
It's been a while since I last used an Omron, but here are my observations on common issues. 1. Check for incorrect wiring. 2. The relays in Omron devices have a high 1,000,000 cycle life, but they can wear out or the contact arm may fail over time. 3. Solid state outputs are rated for a specific amperage, so exceeding this limit with a surge or run current could result in burning the output out. Make sure to conduct proper maintenance to avoid these issues. Regards, James.
Hello James, I am working on a new setup where most of the loads are minor, such as LED lights. The relays I have are brand new and haven't been used yet because I'm unable to establish a proper connection. It has been suggested that the issue may be due to the lack of power to drive the coils on the bus, but I'm unsure how to test for this. Can you provide guidance on troubleshooting power issues in a relay setup like mine? Thank you.
When checking for voltage between the common terminal and the outputs, as well as for continuity, there were no readings. I asked about the Jxx address in case I had entered it incorrectly, but I have confirmed that is not the issue and have removed it. Referring to the diagram provided, the common terminal on the output module is connected to a 24v source. I am conducting tests between 0v and outputs A0 to A7 and B0 to B7. It seems you are communicating clearly, but I am considering different backgrounds and trying to eliminate common mistakes.
- 07-09-2024
- Bering C Sparky
After reviewing the manual further, I have one additional suggestion to try before giving up. Please activate output #1 and check for continuity between A0 and B0. Then, deactivate output #1 and verify if continuity is no longer present. While this may seem like a long shot, it's worth exploring even if it feels like guesswork.
Additionally, consider the possibility that the model number of the card is incorrect, which could explain the issues you are experiencing. Verify if the model number is not OD211 or OC201. If this is not the case, then you may be facing a unique situation. Good luck with troubleshooting.
- 07-09-2024
- Bering C Sparky
When activating an output on the cardigan, can you hear the relay switching?
Wearing a cardigan is not going to solve the problem.
- 07-09-2024
- Ronnie Sullivan
If you are ready, let's proceed with the following steps:
1. First, remove all modules from the plc to start fresh.
2. Clear the program and create a basic test program to ensure the cpu is functioning properly.
3. Install the module in question, which I believe to be a relay module, and disconnect all wiring.
4. Integrate a code to test one of the outputs.
5. Switch off the output and use an ohm meter to test the contacts (A8 (com) to A0-A7 or B8 (com) to B0-B7) to confirm they are open.
6. Activate the output and test the contact again. There should be zero ohms. If everything is connected correctly and working, you should notice a change in ohms.
When it comes to wiring, assuming the plc module will be powering the device:
1. Connect the AC (L1 line) or DC+ to the Com terminals.
2. When the outputs are activated, the contacts will close to provide power to the device.
3. Connect one side of the device to outputs A0-A7 or B0-B7.
For AC power, the wiring is not critical, but for DC power, follow the instructions carefully.
4. Connect the other side of the device to AC neutral or DC common.
I have explained the steps in basic terms to ensure clarity. Thank you, James.
There is a lack of connection between the outputs, and no sound of clicking in the cardigan or module casing.
Hello James, I have completed all necessary steps and am currently testing with only the CPU and output module connected. I have erased the memory and uploaded a program that specifically triggers relays 1 to 4. Despite these efforts, I am encountering the same issues. There may be a configuration issue or possibly damaged hardware causing the problem. I have tested multiple output modules, all of which have shown the same results. It is important to note that all equipment is brand new. While I am new to PLC programming, I have experience with electrical systems. It is perplexing that the indicator LEDs are functioning properly, indicating that the CPU is transmitting the correct instructions, yet the coil remains unenergized. Could there be a BIOS setting affecting this issue?
Have you ever considered grounding the negative side of a circuit for better electrical safety?
If the model number you provided is accurate, then these troubleshooting steps appear to be your best course of action, as outlined in the manual.
- 07-09-2024
- Bering C Sparky
That wraps it up for now. I'll be upgrading my CPU next week and will keep you posted on the results. Your input and assistance have been greatly appreciated, thank you for your contributions and enjoy your weekend!
If there is a removable wiring connector that connects to the front of the output card, try disconnecting all wiring from the connector. Use an ohmmeter to test the continuity between the COM and relay output terminal(s). Make sure to check for any issues with the connector itself by removing it and checking for any damage or seated pins. It is important to inspect all connectors for bent or retracted pins. Make sure everything is properly connected and that a conductive termination connector may be required. If there is no continuity between the COM and output contacts, do not connect a load at this time.
Hello JRB, thank you for your suggestions. I have tested various connectors and three different output modules, but without any luck. At this point, I suspect that the issue lies within the CPU itself. Therefore, I am planning to purchase a replacement CPU to resolve the problem.
To improve your Programmable Logic Controller (PLC) system, consider replacing the faulty relay with an unused one. If you're not comfortable with soldering, consult an electrician for assistance. Alternatively, you can reconfigure the PLC online by changing the address of the faulty relay to match the unused relay. Then, rewire the connections from the faulty relay to the new one for optimal performance.
If you've discovered a faulty PLC, it's crucial to always back up your data and store it on your computer. Invest in a new PLC CPU, upload the program to the CPU, and power up your machinery. We hope this information proves beneficial to you. Thank you.
Thank you so much for your help, it was incredibly beneficial.
Welcome, friend! If you need more information about different types of Programmable Logic Controllers (PLCs), don't hesitate to reach out. Thank you!
After receiving the replacement CPU, I installed it into the system, but unfortunately, there was no improvement in performance.
Share your wiring on OC211 and upload an image (JPEG) of your PLC with IO online. If possible, also share your program for troubleshooting and assistance.
Inspect PD022 to ensure all pins are intact and not damaged. Have you properly connected a 24VDC external power source to the DC 24V input terminals of your PD022 and verified that the PD022POWER Indicator is illuminated?
Below is a duplicate of the program.
JRB instructed to inspect PD022 for any signs of damage to the pins like bending, missing, breaking, or retracting. After checking, ensure that an external 24VDC power supply is correctly connected to the DC 24V input terminals of your PD022, with the PD022POWER Indicator illuminated. Confirm by clicking to expand and selecting "Yes."
Greetings and a warm welcome to the Forum! alphatargets mentioned that they currently have only the CPU and output module connected. It's important to note - are you also utilizing a CJ1W-TER01 Terminating End Cover on the right side of the Output module during testing? This component is essential for properly terminating the bus. Make sure to include this in your setup for successful testing. Thanks for sharing, George.
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Geospark mentioned: Welcome to the Forum! Have you ensured the installation of a CJ1W-TER01 Terminating End Cover to properly terminate the bus to the right of the Output module during your testing? It's an essential step to ensure proper functioning. Regards, George. Hi Geospark, yes, the end cover is already in place, and I have tested a replacement as well. The only component remaining unchanged is the power supply, but I plan to acquire a new one tomorrow.
Looking for a way to check if there is a 24v power supply on the bus?
The root cause of the issue was traced back to a defective Omron CJ1W-PD022 power supply unit, failing to deliver the necessary 24v to activate the relay coils. Grateful for the assistance and input provided by everyone in solving this issue.
I am amazed by how uncommon this is! I have never experienced a failure with my DC power supplies, as I exclusively use them instead of AC power supplies, along with a separate switchmode to power all my devices. It's truly a unique occurrence.
It is quite uncommon, but I encountered a defective CJ1W-PA202 AC power supply from a batch of 40 units. Luckily, OMRON swiftly replaced it through their efficient RMA process.
Alphatargets confirmed, "Hi Geospark, I have already checked and replaced the end cover as a precaution. The only component left to replace is the power supply, which I plan to get tomorrow. Thank you for sharing, I was starting to go crazy trying to solve this problem."