Which absolute encoder is convenient to connect to a PLC? Almost all PLCs on the market now have RS485 communication interfaces. Here we introduce an absolute encoder with an RS485 communication interface.
Easypro absolute encoders (single-turn or multi-turn absolute encoders) feature an RS485 output interface, allowing connection to the RS485 communication interface of any PLC on the market to read encoder data, eliminating the need for a high-speed counting module. They can also directly read encoder data via a microcontroller's communication connection. Currently, Easypro supports various communication protocols to meet diverse user needs.
1. Modbus RTU Easypro. Compliant with the international standard Modbus RTU communication protocol, it is compatible with all PLCs equipped with Modbus RTU. The Easypro encoder has its own software setting interface, allowing intelligent configuration of the encoder's address, baud rate, resolution, and zero position. The PLC's RS485 communication interface can connect 1-9 Easypro encoders with different addresses in a bus configuration. Many PLCs now have built-in Modbus RTU programming protocols.
Second, Easypro 1.0 . Addressing the slow addressing communication issue of Modbus RTU, Easypro 1.0 is configured so that the encoder is in communication host mode and the receiver (PLC or microcontroller) is in receive mode. This eliminates the need for addressing and allows for direct and rapid data reading. In the Easypro encoder software interface, the address is set to 0, and the baud rate and encoder resolution are adjustable according to user needs. Simplified communication protocol: Data format: 8 data bits, 1 stop bit, no parity; ASCII encoding : 13 bytes, starting with "=", 1 byte sign, 10-bit code value; ending with "↙". It can connect to the PLC's RS485 communication interface. However, since the receiver (e.g., PLC) is in passive receiving mode (encoder in active mode), only one Easypro 1.0 encoder can be connected to one communication interface. In encoder active transmission mode, the receiver does not need to receive signals all the time. Instead, the CPU scans and reads the communication sent by the encoder only when encoder data is needed. It first finds the start bit, reads the data in the order of the communication protocol, and decodes it.
3. Easypro 1.1 . The Easypro encoder address is set to 1-9. The encoder uses a bus-type passive communication mode, while the receiving end (PLC or microcontroller) uses a bus master mode. Setting the Easypro encoder address to one of 1-9 allows the PLC master to easily read data based on the address. The baud rate and encoder resolution are adjustable according to user needs. Compared to Modbus RTU, this version is simpler and saves time. The disadvantage is that the bus-type connection can only connect 9 encoders.
Data format: 8 data bits, 1 stop bit, no parity; ASCII encoding : 13 bytes, starting with "=", 1 byte sign, 10-bit code value; ending with "↙". It can connect to the PLC's RS485 communication interface. The PLC receiver is in master mode (encoder in passive addressing mode), and one communication interface can connect 1 to 9 Easypro1.1 encoders . Note that the more encoders connected, the longer the addressing cycle reading time will be. In most cases, the time allotted for reading data from each encoder is 50ms .
Fourth, Easypro 2.1 . This is a simpler and easier-to-understand RS485 communication protocol. It includes a checksum, has an extremely low error rate, strong anti-interference capabilities, and is suitable for all PLC free communication protocols, as well as for user-developed microcontrollers.
The Easypro2.1 absolute encoder (single-turn or multi-turn absolute) is an active broadcast transmitter (capable of receiving from multiple receivers).
For example, two or more PLCs can receive the data for synchronous comparison. The baud rate is 19200, and the data is transmitted at 8ms intervals. The data is 16-bit pure binary code, including checksum and XOR check codes. Decoding is easy, and error code detection and elimination are performed.
It features an RS485 communication interface that can connect to a PLC. Since the receiver operates in passive reception mode (the encoder operates in active broadcast transmission mode), only one Easypro2.1 encoder can be connected to a single PLC communication interface. However, the communication transmission of a single Easypro2.1 encoder can be received by multiple receivers (PLCs, microcontrollers, industrial PCs, or RS instruments), enabling dual control and dual display at both near and far ground levels, or automatic control combined with the Internet of Things (IoT) . In the encoder's active transmission mode, the receiver does not need to constantly receive this broadcast signal; instead, the CPU scans and reads the broadcast communication sent by the encoder only when encoder data is needed, first finding the data start bit and reading the data according to the communication protocol sequence.
5. Easypro2.1K : This is a fast version of Easypro2.1 , with a baud rate of 115200 and a broadcast interval of 2ms. 6. Easypro2.2 : While Easypro2.1 only provided one set of encoder data, Easypro2.2 provides multiple sets, including the electronic revolution count value added by the absolute single-turn encoder, the rotational speed, the encoder's preset address code, or the value of a full-stroke mechanical gearbox-type absolute multi-turn encoder (up to 32 bits). The rest is similar to Easypro2.1 .
7. Easypro2.2K , an accelerated version of Easypro2.1 , with a broadcast interval of 2ms and a baud rate of 115200. 8. Easypro communication and connection with various PLCs:
Easypro RS485 encoders have been widely used in various PLCs for 8 years, including Siemens 200, Siemens 1200, Schneider, Omron, Haurel, Delta, and domestic brands such as Shenzhen rectangular and Xinjie. In particular, it has broken the previous pattern in the domestic market where only Profibus-DP and SSI absolute multi-turn encoders were available, bringing great convenience to connecting and using absolute encoders with economical PLCs.
1. Typical applications of Modbus RTU Easypro: automatic information control for sluice gate networks, various PLCs, especially Schneider and Omron PLCs.
It has many applications.
2. Typical applications of Easypro 1.0 : alignment and synchronization in packaging machinery and printing machinery. It is widely used in both imported and domestically produced economical PLCs.
3. Typical applications of Easypro1.1 : 2-3 encoder bus-type network control applications, such as the rotation and elevation angle control of communication antennas and solar power generation. Among them, projects with Omron PLCs have been exported in batches.
4. Easypro 2.1 and later versions are simpler and faster communication encoders, especially for broadcast-style multi-receiver synchronous reception, which is particularly suitable for multi-machine synchronous control. It is compatible with almost all PLC RS485 communication interfaces with free protocols, such as multiple variable frequency motors for synchronous control.
5. Are there faster communication encoders? For faster communication requirements, it is recommended to choose SSI's synchronous serial communication absolute encoder, which will be introduced in another article later.
The programming and reading programs for the Easypro RS485 absolute encoder and PLC mentioned above are provided free of charge, along with typical application examples. Users who need the programs can contact Shanghai Jingpu Electromechanical Co., Ltd., and be directed to the Marketing Department for technical support.
