How to Measure Length with FX5U PLC Encoder Input

While the Fx series offers 8 high-speed inputs, it is recommended to connect to X0 onwards to avoid issues with processing time. It is important to note that using more than two 2-channel encoders may impact the operation of the system. Depending on whether you are using an FX3U or FX5 controller, there may be differences in functionality. Although I have not personally used the FX5 high-speed inputs, I am aware that they have an FX3 compatible mode. For more detailed information, refer to the manual at https://dl.mitsubishielectric.com/dl/fa/document/manual/plcf/sh081805eng/sh081805engf.pdf.

• 19-01-2025
• parky

Parky pointed out that despite the FX having 8 high-speed inputs, it is typical to connect from X0 onwards. It is possible that using more than two 2-channel encoders may result in operating issues due to processing time. The model being an FX3U or FX5 could impact its functionality, with differences between the two. Though not experienced with FX5's high-speed inputs, there is knowledge of a FX3-compatible mode. To delve deeper into the specifics, consulting the manual at https://dl.mitsubishielectric.com/dl/fa/document/manual/plcf/sh081805eng/sh081805engf.pdf may be beneficial. Just as Parky suspected, the model in question is actually a FX5U, which was inadvertently omitted earlier.

• 19-01-2025
• kawhi

I have a question regarding encoder usage to determine conveyor direction and activation distance for an actuator. I believe I may need multiple inputs to gather rotation information, with more phases allowing for increased pulse count per rotation. However, I am unsure about the number of channels needed for additional encoders. Can you confirm if my understanding is correct? Let me know if I am on the right track.

• 19-01-2025
• kawhi

The setup of your system will dictate the number of inputs needed for the PLC to control the conveyor's direction. Using a 2-phase setup may be beneficial in some cases. Watch this informative YouTube video on how to program a Rotary Encoder High-Speed Counter in a Mitsubishi FX5U IQ-F Series PLC for monitoring linear axis positions. Although I only have an FX3 and no encoder or FX5, if the PLC can determine the direction of movement, a single phase input may suffice. By resetting the high-speed counter with the motor's initial pulse, you can easily track movement and trigger actions accordingly. Consider the operating logic of your system to decide the most suitable setup, as continuous counting in incremental mode may lead to issues when reaching maximum counts.

• 20-01-2025
• parky

When setting up a system with a PLC driving a conveyor, the choice between using a single high-speed input or a 2-phase input will depend on various factors. For instance, if the PLC is already controlling the direction of the conveyor, you may only need one high-speed input. However, using a 2-phase input may sometimes be more beneficial. For a detailed guide on programming a Rotary Encoder High-Speed Counter in a Mitsubishi FX5U IQ-F Series PLC, check out the YouTube video titled "Program Rotary Encoder High-Speed Counter in Mitsubishi FX5U IQ-F Series PLC." This programming feature is commonly used to track the position of a linear axis. Even if you are using a different model like the FX3 instead of an FX5 with an encoder, you can still work with a single phase input as long as the PLC can determine the direction of movement. For example, you can reset the high-speed counter when the motor starts running with a pulse or a oneshot signal. By knowing the direction of movement, you can appropriately energize the system at a specific pulse count. Consider the specific requirements of your system - can the conveyor operate in just one direction, or does it need to be reversible? Using incremental counting may lead to reaching the maximum count before reversing, so it is essential to set parameters accordingly. In manual mode, you have full control over the conveyor's movements, while in automatic mode, it should operate in a single direction. The PLC is responsible for driving the conveyor in both scenarios. The mentioned YouTube video provides a helpful demonstration for programming the Rotary Encoder High-Speed Counter, offering valuable insights for optimizing your system's performance.

• 20-01-2025
• kawhi

The resolution needed depends on the conveyor system's requirements for part processing and inspection. Assuming there is a conveyor with parts undergoing testing for quality control, including a reject station for defective parts further down the line. In this scenario, utilizing a single high-speed input may suffice without the need for an encoder. For instance, integrating a proximity sensor (which can also work with an encoder) and setting input X0 as an interrupt with a proximity and star wheel to detect a specific pulse frequency per millimeter can be beneficial (based on the required accuracy for reject decisions). In the interrupt routine program, establish a bit shift operation with sufficient bits to cover the distance (e.g., assuming a pulse every 5mm of the conveyor). Upon receiving a pulse, assign a value of 1 for a part to be rejected, or 0 for no rejection or no part, and then shift the bits accordingly to determine the part's position on the conveyor. Activation of the reject process can be as straightforward as turning on a specific bit. This method has been successfully implemented numerous times, even managing data within registers to handle barcode information for different parts and diverting them to various sections along a long conveyor system. In practical terms, it was discovered that for a 60m conveyor, it took 1000 pulses from the star wheel for a part to travel from the reader to the last divert station. This effectively divides the conveyor into 1000 segments at intervals of 6mm per shift. By identifying the register position corresponding to each divert station and comparing it to the required code, parts can be accurately diverted when necessary.

• 21-01-2025
• parky

Understanding the intricate process of clay extrusion is key to achieving the desired results. At the end of the process, an extruder releases the clay material. To enhance precision, an encoder is installed at the end of the extruder. This encoder works in conjunction with a rotating conveyor and a cutter, which is activated based on a pre-set distance input on the HMI. The encoder calculates this distance and ensures the clay is cut at the precise moment, providing the perfect outcome for your project.

• 21-01-2025
• kawhi

Ah, I understand. It should be a simple process - just reset the count at the beginning of extrusion and then activate the cutter at the specified distance. I've actually worked on a similar project before, although it involved vertical extrusion. As the pipe was extruded, it would hit a spring-loaded stop plate that moved down to stabilize the pipe. When the encoder reached a certain count, the pipe would be cut at the extruder head. The encoder, located on the stop plate, was driven by a flat gear to convert the pulse into millimeters. I believe this conversion can be done within the settings of the FX5. In my case, it was just a matter of using some basic math to convert the pulses into millimeters.

• 21-01-2025
• parky

Should the count be reset at the beginning of extrusion or when the cutter is activated? The encoder remains operational as long as the extruder is in use.

• 22-01-2025
• kawhi

When our encoder returned after cutting the pipe on the moving plate, it would give a pulse on the return. To ensure accuracy, we implemented a pulse reset of the count before starting the extrusion process. This system was designed for small-length pipes, typically around a meter long (with a range of 300mm to 1000mm). The pipes were positioned vertically, not horizontally. As the pipes moved down the line after cutting, sensors along the line would detect if the pipe was the correct length or if any parts had fallen off. The checking station had about 8 adjustable sensors that would cross-reference the position of the pipe based on preset parameters. If any sensors were not covered when the pipe reached the checking station, it would be considered a faulty pipe. Eventually, this system was upgraded to a camera system with a database of accurately formed pipes for inspection.

• 22-01-2025
• parky

I've noticed a slight difference here - unlike others, we don't rely on sensors post-extrusion.

• 22-01-2025
• kawhi

The testing station was originally used to ensure the pipe's shape was correct. The extruder featured a photocell connected to a drop plate that would trigger the cutting of the pipe once it reached a sensor. However, the operator had to manually adjust the sensor to set the pipe length. To improve efficiency, a decoder was added to allow for recipe loading from the HMI. Additionally, the extruder head was equipped with a mechanism for swaging the pipe end to create a socket for connecting to the next pipe. Despite plans to automate the testing station, it was never completed for unknown reasons.

• 22-01-2025
• parky

Parky explained that the testing station was originally used to ensure the pipe's shape was correct. The original extruder featured a photocell linked to a drop plate, which would trigger the cutting of the pipe once the plate reached a sensor. However, the process required manual adjustment of the sensor by the operator to set the pipe length. To streamline this process, an upgrade was implemented utilizing a recipe loaded from the HMI. A decoder replaced the manual sensor adjustment, making the operation more efficient. The extruder head also included a feature to swage the pipe end, creating a socket for connecting to the next pipe. The automated testing station was planned but never completed. Additionally, VFD technology was considered for controlling conveyors, extruders, and other equipment.

• 22-01-2025
• kawhi

I agreed to work on the extruder, an existing system that I did not delve into deeply in terms of how it operated. I quickly assessed the original control set-up and compared it to the desired functionality. The conveyor system was connected directly to power, with a mechanical adjustable gearbox that I vaguely recall.

• 22-01-2025
• parky

Sure, one more important aspect to note is that, in order to link the encoder, the HIOEN must be utilized. For instance, in stage 3, the instruction HIOEN K0 (for initiating the high-speed counter) will be triggered by K1 K1. When the value SD4500 (which represents the distance converted into pulses) is reached on the HMI, the counting process halts. This value will also reset the high-speed counter through the command DHCMOVP K0 SD4500 K0. Although I have not conducted any tests yet, I am actively exploring and familiarizing myself with these commands.

• 22-01-2025
• kawhi

I am uncertain about the FX5 as it differs slightly from the FX3. The FX3 features counters starting from C235 for high-speed counts. To enable the counter in the program, use TRUE (SM400, or M8000 for FX3) onto C235. To reset it, simply enter 0 into SD4500. Apart from the reset method, to measure the pipe, enable the HS count and ensure it is at 0. When the count reaches or exceeds the desired value, stop the counter, reset it, and activate the cutter. Use >= compare to avoid going past the required count due to slower processing of the main program compared to the high-speed count. Consider adding a slowdown before reaching the final position to account for any drive inertia and reduce errors. You can also factor in an in-flight adjustment by subtracting a small number of counts when it reaches the required value before making the cut.

• 22-01-2025
• parky