S0 pulse counter with MODBUS RTU interface TDI340

Pulse Counting for Industrial Applications - MODBUS RTU TDI340

The TDI340 is an S0 pulse counter equipped with a MODBUS RTU interface and features 4 isolated digital inputs, all complying with the S0 standard 62053-31. This counter operates in either polling or edge modes, with the edge mode capable of counting on rising, falling, or both edges.

In essence, the device incorporates 4 independent counters, with their information securely stored in non-volatile memory to prevent data loss. Beyond raw impulse data, the device offers registers for true physical values, making it ideal for recording energy, water, gas, and more directly.

The device is designed specifically for pulse counting and provides simultaneous readings of the digital inputs' state (OPEN/CLOSE).

Furthermore, it supports independent delays for Low-To-High and High-To-Low transitions ranging from 0 to 656 seconds in 10ms increments, particularly useful for additional digital pulse filtering.

With a wide supply voltage range spanning from 5 to 30 volts, it is well-suited for various industrial applications.


  • RS-485 interface accommodating up to 63 nodes
  • Non-volatile memory for counter storage
  • Broad supply voltage range from 5VDC
  • Low power consumption
  • Galvanically isolated inputs
  • Multiple communication settings
  • Non-volatile memory for storing configurations
  • Built-in 120-ohm termination resistor
  • DIN rail mounting
  • Firmware updates via the interface


  • Remote monitoring of electricity meters
  • Industrial process control
  • Remote monitoring of water meters
  • Monitoring devices with S0 outputs
  • Remote data acquisition
  • Remote monitoring of gas meters
  • Energy management
  • Process monitoring

This counter can be used with the Energy monitoring module TCW260 and third-party MODBUS RTU master devices.

Technical Properties:

  • Physical characteristics
  • Dimensions: 35x86x59mm (2 module enclosure)
  • Weight: 60g
  • Mounting: On 35 mm DIN top-hat rail
  • Environmental limits
  • Operating temperature range: -20 to 60°C
  • Operating relative humidity range: 10 to 90% (non-condensing)
  • Storage temperature range: -25 to 65°C
  • Storage relative humidity range: 5 to 95% (non-condensing)
  • Ingress protection: IP40 (connections IP20)
  • Power supply
  • Operating voltage range (including -15/+20% according to IEC 62368-1): 5 to 30VDC
  • Current consumption: 50mA@5V
  • Digital inputs
  • Isolation: Functional, 1kV DC
  • Independent modes: OPEN/CLOSED (“Dry contact”) and COUNTER (S0 compatible)
  • Maximum count value: 232
    - 1
  • Maximum input voltage: +5.5VDC
  • Maximum source impedance for “0” reading: 800Ohm
  • Minimum source impedance for “1” reading: 1MOhm
  • Current max. (With 0-ohm source impedance): 3mA
  • Maximum frequency for edge counter mode: 100Hz
  • Polling period: 10ms
  • L-H/H-L transition delay interval: 0 to 65535 x (polling period); not available for edge counter mode
  • Interface
  • Protocol: Modbus RTU
  • Physical layer: RS-485 serial line
  • Number of bus transceivers: up to 63
  • Bus cable: Twisted, shielded, 2×0.5mm²
  • Response time ≤ 50ms
  • Master response time-out ≥ Response time + Answer time
  • The answer time depends on the number of bits and the baud rate.
  • Connectors
  • Type: 3.81mm pitch screwless pluggable for 28 to 16 (AWG) / 0.081 to 1.31 (mm²) wires
  • Warranty
  • Warranty period: 3 years