Category
IO List & Wiring
AI/AO/DI/DO, 4-20mA, 0-10V, NTC, PT1000, signal types
What Is an IO Module in BMS?
An IO module is the extension board of a BMS: a small board that adds more input and output points to an existing controller over a field bus, so a panel can grow without replacing the controller or re-commissioning it.
What Is the Difference Between AI, AO, DI & DO Modules?
AI, AO, DI and DO modules map to four human-like jobs: read a measurement, give a command with strength, read a yes/no, and switch something on or off. Matching the field device to the right channel is the core of every
What Is a BACnet IO Module?
A BACnet IO module joins a BACnet MS/TP or BACnet/IP network as a native device, exposing its points as standard BACnet objects that any controller can discover — with no proprietary converter sitting in the middle.
What Is a Modbus IO Module?
A Modbus IO module exposes each channel as a numbered holding or input register over RS485 (Modbus RTU) or Ethernet (Modbus TCP). The register map and correct scaling turn its raw numbers into real, usable field values.
How Many Channels Does an IO Module Have?
IO modules come in common sizes such as 4, 8 and 16 channels, in dedicated or mixed layouts. Size the module to the IO list with about 15% spare, balancing panel space and cost against future growth.
What Is a Remote IO Module in BMS?
A remote IO module sits near distant field devices and carries their signals back to the controller over a single field bus, cutting long analog cable runs, reducing electrical noise, and saving copper and labour.
How Do You Wire an IO Module to a DDC Controller?
Wiring an IO module means a daisy-chained A/B/GND RS485 bus, a unique address, matching baud rate, end-of-line termination, and clean 24V power. Get these right and the controller sees every module on the trunk.
What Is the Difference Between an AI Module and an AO Module?
An AI module reads an incoming analog signal from a sensor; an AO module drives an outgoing analog signal to an actuator. The difference is direction: AI takes information in, AO sends a command out.
IO List Best Practices — The Color-Code Discipline That Saves Commissioning
Selva's panel has 480 wires. On day-3 of commissioning, channel AI-37 reads minus 41 degC. The wire is from a return-temp sensor. Or is it? Without color-code discipline and labelling, every wire is a guess.
IP-Rated Field Panels for Indian Conditions — Coastal, Dusty, Tropical
Salim's IP-54 panel was fine for Bengaluru. In Chennai, after one monsoon, two relays corroded. The panel is 200 metres from the sea. Indian conditions vary, and one IP rating does not fit all.
Auto-Generated DDC Wiring Drawings — How Modern Engineering Tools Replace AutoCAD Drafting
Sachin's team draws DDC wiring diagrams in AutoCAD or Visio. Every project takes 2-3 days of drafting. Tag changes mid-project mean redrawing every sheet by hand. There is a faster way.
What Are Analog and Digital Signals in BMS?
Your car speedometer does not jump from zero to 100. It moves smoothly — 15, 27, 43, 68, 91. It follows exactly where your accelerator takes it. It can be at any value within its range. This continuously changing value i
What Is an IO List in BMS?
Before smartphones, every city had a telephone directory — a complete list of every person, their address, and their phone number. One organised table. Find anyone instantly.
How to Wire a Relay to a Digital Output (DO)?
Existing page on platform — content already live
What Is 4–20mA Signal in BMS?
Imagine your home water tap. When barely open — very little water flows. When fully open — maximum flow. Between these two extremes, the flow varies proportionally with how much you turn the tap.
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