X-404™ | Modbus RS-485 Module

Engineering & Marketing International

Versatile, Easy Monitoring & Control

  • X-404-I,X-404C-I-CA

The X-404™ is purpose-built to monitor up to 32 Modbus RS-485 devices and/or sensors. It also includes a 1-wire bus for temperature and humidity monitoring.The X-404C offers wireless capability with a built-in, low-power LTE-M cellular radio. Cellular models with an annual data plan include a dual SIM that provides combined coverage through AT&T and T-Mobile, automatically switching between the two for the best coverage.

  • Modbus RS-485 input
  • Up to 16 temperature sensors
  • Cellular version available

Monitor any sensor or equipment that has an RS-485 output with the X-404. It functions as a web-based, cloud-compatible Modbus master for third-party RS-485 modbus sensors and devices. This includes level, current , pressure, temperature, and humidity sensors.

X-404 Features

  • Email Notifications
  • Customizable Web-Based Dashboard
  • Peer-to-Peer Communication
  • Conditional Logging & FTP Log Exports
  • 400 Series Platform
  • Failover From Ethernet (X-404C Only)

X-404 Applications

  • Sensor & Equipment Monitoring
  • Generator Monitoring
  • Temp & Humidity Monitoring
  • Tank Level Monitoring



  • X-404-I: 9-28 VDC
  • X-404C-I-CA: 9-28 VDC

Power Requirements

  • Voltage:
    • X-404-I: 9-28 VDC
    • X-404C-I-CA: 9-28 VDC
  • Max Current:
    • No Modbus Sensors: 134mA
    • X-404 + 1.7A for modbus sensors: 1.834A

RS-485 Connector

  • Sensors Supported: Up to 32
  • Connector: 5-position, removable terminal strip, 3.81 mm spacing
  • Communication: RS-485

Temperature Sensors

  • Maximum Number of Sensors: 16
  • Temperature Range: -67°F to 257°F (-55°C to +125°C)
  • Accuracy: ±0.5°C (from -10°C to +85°C)
  • Sensor Functions: Monitor Temperature, Log Temperature, Email Alerts, SNMP Traps
  • Humidity Type: ControlByWeb Model X-DTHS-P sensor
  • Humidity Range: 0-100% RH
  • Accuracy: ±2%
  • Max Cable Length: 600 feet (180m) maximum combined cable length

Real-Time Clock

  • Manual or NTP(Network Time Protocol) setup
  • NTP Sync Period: Once, Daily, Weekly, On Powerup
  • Auto Daylight Savings Adjustment
  • Battery (capacitor) Power Backup

Capacitor Power Backup

  • Backup Functions: Real-time clock, 1 register, 2 counters, 64 relay states (remote modules only)
  • Backup Duration: 24 hours


  • Type: 10/100 Base-T Ethernet Port
  • Setup: Static or DHCP IP address configuration
  • Wireless: Cellular Modem (X-404C-I only)


  • Modbus Bus: 5-Position, 3.81mm terminal spacing, Removable. For 16-28 AWG wire.
  • Power and 1-Wire Bus: 5-Position, 3.81mm, Removable
  • Network: 8-pin RJ-45
  • Cell Antenna: Male SMA Connector (X-404C-I only)

LED Indicators

  • Number of LEDs: 3
    • Power on
    • Network linked
    • Network activity


  • Operating Temperature: -40°F to 150°F (-40°C to 65.5°C)
  • Size:
    • 1.41in (35.7mm) wide
    • 3.88in (98.5mm) tall
    • 3.1in (78mm) deep (not including connector)
  • Weight: 5 oz (142 grams)
  • Enclosure Material: Lexan 940 Polycarbonate Plastic
  • Enclosure Flame Rating: UL94 V0


  • HTTP, HTTPS, XML, Modbus TCP/IP, SNMP, SMTP, Modbus RS-485


  • Log File Size: 3,072-Kbyte (up to 50,688 logs)
  • Storage: Nonvolatile Flash
  • Buffer Architecture: Circular Buffer

Advanced Features

  • Task Builder
  • BASIC interpreter (up to 4-Kbytes script file size)
  • Remote services

Password Settings

  • Password Length: 6-18 Characters

Electromagnetic Compliance

  • IEC CISPR 22, CISPR 24
  • EU EN55024, EN55022
  • X-404-I: FCC 47CFR15 (Class B)

Product Safety Compliance

  • IEC 61010-1