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Modbus Software Components for Developers

Modbus Peek & Poke


  • Monitor PLC and remote I/O devices
  • Low-level control
  • Stress testing
  • Educational tool - use for understanding Modbus/TCP protocol
  • Troubleshooting aide
  • Equipment demo tool
  • Development tool

Compatible With

  • iPhone 3, 4, 4S, 5, 6
  • iPad, iPad 2, new iPad and iPad Mini, iPad Air
  • iOS 7 and later
  • WI-FI, 3G/4G
  • All portrait and landscape orientations supported

Supports Standard Modbus Functions

  • 01 - Read Coil Status (0x references)
  • 02 - Read Input Status (1x references)
  • 03 - Read Holding Registers (4x references)
  • 04 - Read Input Registers (3x references)
  • 05 - Force Single Coil (0x references)
  • 06 - Preset Single Registers (4x references)
  • 07 - Read Exception Status
  • 15 - Force Multiple Coils (0x references)
  • 16 - Preset Multiple Registers (4x references)
  • 17 - Report Slave ID

Additional Features

  • Send Custom User Request - provides unlimited Modbus functionality
  • Access Raw Request/Response Frames - helpful for troubleshooting
  • Built-in IEEE Single Precision Floating Point Support
  • Visual Connection Status
  • Connected Icon Disconnected Icon
    Connected Disconnected
  • Ping any IP address
  • Access Modbus/RTU devices through a Modbus/TCP to Modbus/RTU gateway


Peek & Poke your Modbus device from anywhere on Earth. 

Peek & Poke Network


Screen Shots (similar for iPhone only scrolls for the smaller display).  Modbus Peek & Poke is made up of five tab views.  Click on an image below to learn more about the particular view.


Settings Tab Settings

Configure the communications properties for your Modbus/TCP server here.

iPad Settings Tab

Test Tab Test

 Peek and poke the registers, discretes and coils of your Modbus/TCP device here.

iPad Test Tab

User Request Tab User Request

Transmit your own custom request and receive the response here.

iPad User Request Tab

Raw Frames Tab Raw Frames

View the hexadecimal bytes for the last request and response here.

iPad Raw Frames


About Tab About

View the version number and other information for Modbus Peek & Poke here.

iPad About Tab