1 Working voltage: DC5V/DC 12V (6-25V)

2 Working current: 8-14MA

3 MODBUS RTU function codes: Write 05/06/15/16, Read 01/02/03

4 5 function IO modes can be selected by jumper: 8DI/8DO/4DI-4DO/2DI-6DO/6DI-2DO

5 By modifying the 0X00F5/0X00F6 register, the input and output levels (NPN/PNP) can be switched

6 Input mode: Support 3.3V/5V TTL level input, there are two input modes of low level input (default) and high level input

7 Output mode: 5V TTL level, low level (default) / high level output

8 In MODBUS command mode, it can support up to 247 devices in parallel

9 Input port status supports query (default) and automatic reporting

10 BaudRate:1200 2400 4800 9600(default) 19200 38400 57600 115200, None/Odd/Even Parity

11 Use the ZH1.5MM Connector to make the board small and thin

12 Size: 44*20*5(Very Small and Very Thin)

13 Weight: 2.8grams(Very Light)

This module is a multi-function board, you can select various function modes through jumpers.
The jumper uses 0603 0Ω resistor (or wire)

Different Versions of Pin Definitions


For MODBUS RTU command details, see:''R4IOH08 MODBUS RTU Commamd''





By modifying the 0X00F5/0X00F6 register, various input and output levels (NPN/PNP) can be switched

NPN Input & NPN Output(Register 0X00F5=0,0X00F6=0,Default)
PNP Input & NPN Output(Register 0X00F5=1,0X00F6=0)
NPN Input & PNP Output(Register 0X00F5=0,0X00F6=1)
PNP Input & PNP Output(Register 0X00F5=1,0X00F6=1)

Note: The board does not include the ZH1.5mm terminal wire, which needs to be purchased separately