X-400™ | Modular I/O Controller


The X-400™ is a web-enabled controller that allows for up to 32 added expansion modules and/or remote I/O devices. Expansion modules are connected directly to the X-400 via ribbon cable, or remotely with other CBW devices via P2P—allowing for monitoring and control of up to 64 I/O.

Expandable, Up to 64 I/O

Relays, Analog & Digital Inputs

Up to 16 temp sensors

Cellular version available

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Total: $299.99

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  • 30-day return policy
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X-400 Overview

The X-400 is a great drop-in solution for flexible data capture and use. The modular design boosts I/O options with a variety of compatible expansion modules. Peer-to-peer networking with other ControlByWeb devices extends reach in physically challenging applications.

X-400 Features

  • Simple Web-Based Dashboard
  • No-Code Logic Builder
  • Peer-to-Peer Communication
  • Ethernet I/O Monitoring & Control
  • 400 Series Platform

X-400 Applications

  • Building Automation & Access Control
  • Process Control
  • Remote/Field Monitoring & Control
  • Dry Contact Monitoring/Notifications
Integration Icon

Integration Ready

We support HTTP GET, XML, JSON, SNMP, Modbus TCP/IP, and our Cloud API with more on the way.

No-Code Logic Icon

No-Code Programmable Logic

Our intuitive Task Builder empowers you to build custom logic using drop-down menus in an if-this-then-that flow.

Peer-to-Peer Icon

P2P Networking & Remote I/O

Devices can communicate through Peer-to-Peer (P2P) networking to share I/O among other ControlByWeb controllers, assign any device as master, set up multiple masters, and link remote inputs and relay control.

Email Notifications Icon

Email Notifications

Stay in control of operations with real-time monitoring. Add intelligence to your emails through programmable logic to instantly send notifications to the right people and eliminate false alarms.

Built-In Firmware Icon

Easy-to-Use Embedded UI

Our devices come with a simple embedded user interface that will enable you to easily monitor, manage, and control ControlByWeb PLCs from any standard web browser.

Data Logging Icon

Data Logging

Enjoy scheduled and conditional logging with email and FTP log exports. Add the optional ControlByWeb Cloud for remote access and downloadable logs.

Cloud Compatible Icon

Cloud Compatible

Enhance your capabilities with the ControlByWeb Cloud. Gain enhanced features such as simplified remote device access, data logging, and advanced analytics.

Security Icon

Trusted Device Security

Our controllers have no built-in OS or file system, making them less prone to vulnerabilities. Third-party consultants and government agencies test the cybersecurity of our controllers.

IIoT Icon

IIoT Monitoring & Control

Access the device directly through an assigned IP address. Set up your network settings the way you want, to limit or allow remote access through the cloud.


X-400 Case Studies

(Example images are shown. Label and terminal connector may differ)


Power Requirements
  • X-400-I
    • Voltage: 9-28 VDC
    • Max Current: (See Table)
Power Supply Input Current (no expansion modules) Input Current (X-400 + 1.7A for expansion modules)
9 VDC 134 mA 1.834 A
12 VDC 101 mA 1.801 A
24 VDC 55 mA 1.755 A
  • X-400C-I-CA
    • Voltage: 9-28 VDC
    • Max Current: (See Table)
Power Supply Input Current (no expansion modules) Input Current (X-400C + 1.7A for expansion modules)
9 VDC 240 mA 1.94 A
12 VDC 185 mA 1.85 A
24 VDC 95 mA 1.80 A
Voltage Outputs
  • Expansion Bus: 1.7A max
Temperature Sensors
  • Maximum Number of Sensors: 16
  • Type: Dallas Semiconductor DS18B20
  • 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
  • Type: 10/100 Base-T Ethernet Port
  • Setup: Static or DHCP IP address configuration
  • Wireless: Cellular Modem (X-400C model only)
  • Power and 1-Wire Bus: 5-Position, 3.81mm terminal spacing, Removable. For 16-28 AWG wire.
  • Expansion Bus: Ribbon cable, 10-conductor, polarized, 2×5-position, 0.100″ pitch Provides power and communications for expansion modules (Communications: RS-485)
  • Network: 8-pin RJ-45
  • Cell Antenna: Male SMA Connector (X-400C model only)
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: Retain Real-Time Clock, 1 Register, 2 Counters, 64 Relay States (local and expansion relays only)
  • Backup Duration: 2 week minimum
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
Email Notifications
  • Email Addresses: 8
  • Encrypted Email Alerts: STARTTLS and TLS/SSL
  • Alert Functions: I/O states – Fully customizable
  • HTTP, HTTPS, SSL, XML, Modbus TCP/IP, SNMP, SMTP, Remote Services
  • Log File Size: 3,072-Kbyte (up to 50,688 logs)
  • Storage: Nonvolatile Flash
  • Buffer Architecture: Circular Buffer

Log data can be periodically read and stored on a computer

Advanced Features
  • Task Builder
  • BASIC interpreter (up to 4-Kbytes script file size)
  • Remote services
  • ControlByWeb Cloud Compatible
Password Settings
  • Password Length: 6-18 Characters
Electromagnetic Compliance
  • IEC CISPR 22, CISPR 24, EU EN55024, EN55022
  • FCC 47CFR15 (Class B)
Product Safety Compliance
  • IEC 61010-1


Manuals & Downloads



IMPORTANT: As a result of recent inline improvements to device hardware, different firmware versions have been created that are equal in functionality, but not cross-compatible. Installing the wrong firmware will not work. Please select the correct firmware for your current firmware version below:

X-400 Firmware v2.81(for firmware versions 2.7 or lower)

X-400 Firmware v3.08(for firmware versions 3.0 or higher)

Firmware updates work on any previous version as long as they are compatible. Note: versions 2.X and 3.X are equal in functionality, but not cross-compatible.

Cellular Model Firmware

X-400C Firmware v2.81(for firmware versions 2.7 or lower)

X-400C Firmware v3.08(for firmware versions 3.0 or higher)


24V DIN Rail Power Supply

24V DIN Rail Power Supply

Cloud Seat Icon

ControlByWeb Cloud Device Seat

Digital Temperature 1 foot long

Digital Temperature Sensor (1ft)

Expansion Cable

Expansion Cable

Magnetic Sensor Mount Kit

Magnetic Sensor Mount Kit

12VDC Power Supply

Power Supply | 12VDC

Submersible temperature sensor

Submersible Temperature Sensor (4m)

Temperature and humidity probe

Temperature/Humidity Sensor (Probe)

Wall Mount Temperature Sensor

Wall Mount Temperature Sensor

Wall Mount Temperature and Humidity Sensor

Wall Mount Temperature/Humidity Sensor

Water-Resistant Digital Temperature Sensor 10 Meters Long

Water-Resistant Digital Temperature Sensor (10m)

Water-Resistant Digital Temperature Sensor 1 Meter Long

Water-Resistant Digital Temperature Sensor (1m)

Water-Resistant Digital Temperature Sensor 4 Meters Long

Water-Resistant Digital Temperature Sensor (4m)

X-11s - 2 high-powered relay device

X-11S™ | High-Current Relay Expansion Module

X-12s - 8 relays

X-12S™ | 8 Relay Expansion Module

X-13s thermocouple expansion module

X-13S™ | Thermocouple Expansion Module

X-15s - eight digital input module

X-15S™ | 8 Digital Input Expansion Module

X-16s - eight analog input module

X-16S™ | 8 Analog Input Expansion Module

X-17s - 4 relay and 4 input expansion module

X-17S™ | 4 Relay, 4 Input Expansion Module

X-18s - 10 high-current relay expansion module

X-18S™ | 10 High-Current Relay Expansion Module

X-19s - 16 relays, 16 digital inputs and 4 analog inputs

X-19S™ | Multi-Purpose I/O Expansion Module

X-20s - 6 relay, 6 digital input expansion module

X-20S™ | 6 Relay, 6 Digital Input Expansion Module

X-21s - four relay form C / SPDT expansion module

X-21S™ | Relay Form C / SPDT Expansion Module

X-22s - Eight analog input expansion module

X-22S™ | 8 Analog Input Expansion Module

For your convenience we have set up a live X-400 unit for testing and evaluation. By clicking the links below you have full access to this live unit. You can make changes to the configuration and settings through the setup pages and you can control X-400 through its control page. The control page allows you to view the current state of the X-15s’ digital input and also the temperature sensor connected to the X-400.

Self Guided Demo With Login and Video

*Setup page login information:

Username: admin

Password: webrelay

Control Page Setup Pages* Digital Input Control Page X-400 live demonstration setup

Live Demo With One of Our Sales Engineers

Let’s make it easy with a live demo and screen sharing.

Set up a one-on-one Q & A with one of our experts. We’ll help you find the best solutions for your next project and walk you through a demonstration.

Low on time? Watch a pre-recorded demo instead:

400 Series Setup and Programming Demo

X-400 Setup

The diagram illustrates how this demonstration is wired. Nothing is connected to the analog outputs; however, you can still turn the output on and off to see how it works.

Important Information

  • Multiple users may be accessing this device simultaneously so the device can change while you are using it.
  • This unit will be reset to factory defaults daily at 2:30AM MST.
  • Please DO NOT change network or password settings.

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