Modbus TCP FieldKit

Modbus TCP FieldKit puts a professional Modbus TCP toolkit in your pocket. Commission equipment in the field, validate setups in the lab, or troubleshoot home automation — all from your iPhone.

• Connect to any Modbus TCP or RTU over TCP device — read coils and registers, monitor data blocks in real time
• Modbus RTU over TCP — reach RS-485 devices through Wi-Fi or Ethernet converters in transparent mode (for example Elfin EW11, USR or Waveshare). If a read times out, the app offers to try the other framing with a single read.
• Find devices and Scan Unit IDs on your own Wi-Fi subnet — ports 502, 1502, 8899 and 4196. Each device is read once and nothing is written.
• Chart every monitored value — the app keeps the last 600 points or 1 hour per value while it is open — and Export CSV through the system share sheet.
• Save device profiles for one-tap reconnection to frequently used endpoints
• Write with confidence — every write operation requires your explicit confirmation
• Built-in foreground simulator — run editable coils and holding registers for testing
• Track active connections and review bounded local logs kept on your device
• All data stays local — logs and diagnostic exports are sanitized by default

Requires Local Network access for device communication. RS-485 devices connect through a Wi-Fi or Ethernet converter in transparent mode. Default server port is 1502. Background server operation and port 502 support pending device validation.