TRP-C28H     Isolated  4 Channel Digital Input with counter and 4 channel AC Relay Modbus TCP Module                      Support  TRP-ASCII, Modbus RTU/ASCII  protocol


The TRP-C28H is a 4-ch digital Input and 4-ch relay Ethernet I/O module with isolation.

It allows the user to connect the signals from 4V to 30V,and the Replay can connect AC voltage directly.

Each contact of relays we built-in safety suge protection to prevent a spark.

It has a normal I/O  except the counter function.

There are 3 protocols we supports that, it includes ASCII and Modbus TCP RTU / ASCII.

The watchdog function ensures running stable under harsh environment.

It allows to connect 1~8 sets of host IP in the network security.


  • Wide input range DC power supply.
  • Automatically determine 3 TRP-ASCII and Modbus RTU/ASCII communication protocol.
  • 16 TCP Port can be open at the same time.
  • Heart Beat function ensures a reliable communicating connection.
  • Maximum 8 sets host IP that limits network access.
  • Support Virtual-COM mode.
  • WEB PAGE can be directly read IO status.
  • Easily update the firmware using the Internet.
  • Back to factory configuration by external touch Button.
  • Auto reconnection when power or Ethernet fail.
  • Digital input signal from +/- 0 to 30V DC.
  • Built-in surge absorber in each relay N.C and N.O.
  • Built-In watchdog function prevents system boot fail. 
  • LED for each I/O channels working status.
  • Support Auto-MDIX twisted pair crossover detection and Auto-Correction.
  • Power/Link/8 CH D I/O LED indicator.
  • DIN-Rail and panel mount support.
  • Dual power input select from screw terminal or DC-Jack..


  • Power Input Voltage DC +10V to +30V.
  • Protocol: TRP-ASCII and Modbus RTU/ASCII.
  • Input channel: 16 digital input channels with counter.
  • Input digital input counter: 0~65535.
  • Input optical isolation: 3750 Vrms.
  • Input logical level 0 +1V (max).
  • Input logical level 1 +4.0V ~ +30V.
  • Output channel: 4 channel power reply outputs.
  • Relay type: 2 Form A (RL1,RL2) , 2 Form C (RL3,RL4).
  • Contact ratting: 5A /30V DC , 5A /120V AC , 5A /250V AC.
  • Relay surge strength: 4000V.
  • Relay operating time: 3mS.
  • Relay operating life: 2 X 10(7).
  • Communication interface: Ethernet RJ45.
  • Configuration mode: Trycom Device Manager, WEB settings.
  • Matching remote control: with another TRP-C28H.
  • Heart Beat: TCP Port sent string every 5 seconds.
  • TCP Maximum Connection:1~16.
  • Module ID :1~255.
  • Connection type: Screw terminal for maximum AWG 12 wire.
  • Power supply: Screw terminal, or external DC adapter.
  • Power consumption 320mA/12V.
  • Operating environment: 0 to 50℃.
  • Storage temperature:. -10 to 70℃.
  • Humidity: 10~90% Non-condensing.
  • Dimension: 151mm X 75mm X 26mm .
  • Weight: 395g .


PWR-AD12VAuto (Option)

Switching Adaptor

Input:100~240VAC 50/60Hz 260mA

Output: DC 12V/1A

Certificate: CE, FCC, UL, PSE

US Specification  

We also provide the EU / AUS / British specifications(MOQ:50PCS/2 Weeks)…...more

DIN-RAIL-R (Option)

DIN rail mounting adapter