USB TO 8CH RS485
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Overview
Introduction
USB TO 8CH RS485, an industrial USB to RS485 isolated converter with a rail-mount case, features the original CH348L chip and built-in protection circuits such as power isolation, ADI magnetical isolation and TVS. This converter is easier to operate due to its fully automatic transceiver circuit with no delay. Boasting characteristics of fast communication, stability, reliability, and safety, it is an ideal choice for various industrial control devices and applications with high communication requirements.
Features
- Supports USB to 8CH RS485, convenient for expanding multiple RS485 industrial serial devices.
- Supports direct power supply via Type-C port, with reserved 5V~36V DC wide voltage screw terminal for auxiliary power input.
- Onboard unibody power supply isolation, provides stable isolated voltage.
- Onboard unibody digital isolation, allows signal isolation, high reliability, strong anti-interference, low power consumption.
- Onboard TVS (Transient Voltage Suppressor), effectively suppress surge voltage and transient spike voltage in the circuit, lightningproof & anti-electrostatic.
- Onboard self-recovery fuse and protection diodes, ensures the current/voltage stable outputs, provides over-current/over-voltage proof, improves shock proof performance.
- Built-in 120R terminal resistor on the RS485 ports, configurable via jumper for flexible switching.
- LEDs for indicating the power, device configuration status and transceiver status.
- Rail-mount case design, support stackable combination, easy to install and safer to use.
Parameters
| Product Type | Industrial Isolated USB to RS485 converter | ||
| Host Interface | USB | ||
| Device Interface | RS485 | ||
| Power Supply | USB Type-C (5V), screw terminal (5V~36V) | ||
| USB Interface | Operating Level | 5V | |
| Connector | USB-C | ||
| Interface Protection | 200mA self-recovery fuse, isolated output | ||
| Transmission Distance | About 5m | ||
| Isolated RS485 Interface | Connector | Screw Terminal | |
| Direction Control | Hardware automatic control | ||
| Protection | 600W lightningproof and surge-suppress, 15KV ESD protection (onboard 120R balancing resistor) | ||
| Transmission Distance | About 1.2km (low rate) | ||
| Transmission Mode | Point-to-multipoints (up to 32 nodes, it is recommended to use repeaters for 16 nodes or more) | ||
| Baud Rate | 1200bps ~ 921600bps | ||
| Indicator | PWR | Red power indicator, lights up when there is USB connection and voltage is detected | |
| ACT | Status indicator, lights up green when the driver is detected. | ||
| TXD | Green TX indicator, lights up when the USB port sends data | ||
| RXD | Blue RX indicator, lights up when the device ports send data back | ||
| Operating Environment | Temperature | -15 ~ 70℃ | |
| Humidity | 5% ~ 95%RH | ||
| Operating System | MacOS, Linux, Android, Windows 11/10/8.1/8/7 | ||
Onboard Interface
Dimensions
Driver Installation
- First, download the driver file USBMESR.
- Double-click USBMESR.exe and install it by steps.
- Select USB to serial ports (USB 1.1/2.0) as card type.
- Click on Install Driver.
- When the progress bar is loaded, a pop-up window will appear to indicate that the driver has been installed successfully.
- After connecting to the computer, you can find the available ports and their corresponding COM port. (Also, you can assign the COM port number through the serial port manager tool).
Communication Operation
- Open SSCOM software.
- Generally, it can identify 8 COM port.
RS485 Communication
The following displays how to perform the communication between two channels.
Hardware Connection
| USB TO 8CH RS485 | |
| A1 | A2 |
| B1 | B2 |
Software Operation
- Open two SSCOM interfaces.
- Select the corresponding COM port of channel A and channel B, respectively.
- Select the baud rate as 115200, input the characters you want to send, check Show time and packet, and click on Open COM.
- Select 100ms intervals in two SSCOM interfaces, and you can see they transmit and receive data normally, the effects as shown below:
Resource
Datasheet
Software and Drivers
- SSCOM Assistant
- Windows USBMESR driver (or download from WCH website)
- Linux Driver
FAQ
Answer:
- Generally, USB power is sufficient. For some older computers with insufficient USB power, DC power can be used.
- If multiple channels are used simultaneously, multiple devices are connected, and the communication distance is long, causing insufficient drive capability, DC power is needed. TTL power consumption is relatively low.
Answer:
- RS485 is half-duplex communication. You can test data transmission and reception by connecting two channels together.
- The following example uses Port1 and Port2 to test data transmission and reception. Ensure the correct COM ports are selected; the corresponding channel indicators will flash.
- If data is exchanged between the two channels, the module itself is functioning properly.
Answer:
- Mainstream serial assistant tools such as SSCOM, SCOM, and PuTTY are supported.
- There are many tools available, and we cannot verify each one. Therefore, we cannot guarantee that other industrial control software will work. Please use the bundled sscom serial tool as a priority.
Answer:
- This is a driver issue. Download the Linux driver.
- Compile and load the USB device descriptor using:
sudo make install
- The figure below is tested on a Raspberry Pi with the 240704 64-bit Bookworm system. Different systems may vary; please modify the operations according to your actual situation:
- It is recommended to use tools like cutecom to access the serial port; minicom may experience lag issues
Answer:
1. After connecting the device to the computer via USB, open Device Manager.
2. Under the "Ports" section, you will see the corresponding serial port numbers.
3. Right-click on the port you want to view and select "Properties".
4. After entering, you will see more status information about the port, as shown below.
Answer:
- The USB and the eight RS485 channels have signal and power isolation to reduce ground loops, electromagnetic interference, and surges affecting the USB host and RS485.
- The relevant components themselves have an isolation withstand voltage rating of approximately 1kVDC. For very short transient high voltages (instantaneous spikes near 1 kV), they can effectively prevent breakdown, thus reducing the risk of direct damage to the module and the USB host.
Support
Technical Support
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