1-channel encoder pulse counter or 2 DI high speed counter, Modbus RTU module
S0 pulse counter with MODBUS RTU interface - TDI340
Pulse Counter Frequency Data Module 32-bit 1mhz Digital Input Output Encoder Input Rs485 Modbus Adam Din Rail - Instrument Parts & Accessories - AliExpress
MiOYOOW DC 12V Pulse Counter High Level Trigger Relay Module 0-10kHz Frequency Counter for Motor Speed Hall Sensor : Amazon.de: Business, Industry & Science
Amazon.com: Pulse Counter Relay Board, Easy to Install 1 Channel 0.1S to 9999999.9s Multifunctional Pulse Counter Relay Module for Industry(12V) : Electronics