Serial Tap

Serial Tap

The Serial Tap is an affordable sniffer for monitoring RS232, RS485, and TTL-level UART communications. The sniffer taps into the data and control lines of serial links and sends the recorded data to IO Ninja software in real time.

All inputs of the serial tap are available on a quick-release terminal block. The Tap also features two DB9 connectors for "wedge" monitoring of RS232 communications. The board even provides jumpers for swapping and loopbacking RS232 signals, as well as bi-color LEDs for RS232 line status indication. The jumpers and bi-color LEDs give the Tap an additional use as a simple tool for debugging RS232 wiring issues.

This sniffer device must be used with the Serial Tap plugin.

Key Features

  • USB-powered, no additional external power necessary
  • Supplied with a USB-C cable and two DB9 gender changers
  • Three operating modes: RS232, RS485, and TTL-level UART
  • Quick-release terminal block facilitates convenient wiring
  • Monitoring of TX, RX, RTS, CTS, DTR, and DSR lines
  • Onboard LEDs for line status indication
  • "Wedge" monitoring of RS232 communications:
    • DB9 connectors for placing the Tap "between" RS232 devices
    • Jumpers for swapping and loopbacking RS232 signals within TX/RX, RTS/CTS, and DTR/DSR signal pairs
    • Bi-color LEDs for distinguishing between positive, negative, and zero voltage levels on RS232 lines

Hardware Specifications

USB:USB 2.0 interface, full-speed (12MHz), USB-C connector
Maximum RS232 baud:Up to 1Mb/sec
Maximum RS485 baud:Up to 3Mb/sec
Maximum TTL-level UART baud:Up to 3Mb/sec
Supported TTL logic levels:From 3.3V to 5V
Operating temperature:0 to +60 degrees C
Operating relative humidity:10% to 90%
Mechanical dimensions:82 x 74 x 30 mm


Hardware Manual (HTML)

This is the I2C/SPI Tap chapter in the IO Ninja hardware manual.

Hardware Manual (PDF)

This is a PDF rendition of the above online HTML manual for downloading and printing.