How to Mount DIN Rail Computers

DIN rail mounting is a way of fixing electrical and electronic equipment to a standard metal rail, most often the 35 mm top-hat rail defined in IEC/EN 60715, by hooking a spring clip over one edge of the rail and snapping it over the other. Circuit breakers, terminals, power supplies, PLCs and, increasingly, industrial computers all share the same rail, so a control cabinet can be laid out, extended and rearranged without drilling new holes.

For a computer, the attraction is the same as for any other device on the rail: it goes in quickly, sits in line with the equipment it talks to and can be moved or replaced in minutes. Our DIN rail PCs come with the clip fitted, and many of our box PCs take an optional DIN rail kit. This guide covers the rail types and sizes, how to mount and remove a DIN rail computer step by step, the thermal clearances a fanless system needs, and what to do with heavier systems and vibration.

DIN rails take their name from the Deutsches Institut für Normung, the German Institute for Standardization, which published the original rail specifications. The profiles were later adopted as European and international standards, now IEC/EN 60715, so the same rail and the same clip fit equipment from any manufacturer worldwide.

The rail itself is a strip of zinc-plated or chromated steel, sometimes aluminum or copper, with a hat-shaped or C-shaped cross-section. Our FAQ on what a DIN rail is gives the short answer; the sections below go into how to choose a rail and mount a computer on it.

Most industrial computers use the 35 mm top-hat rail, but several profiles are still in service. The DIN rail mounting kits on our computers fit both depths of the 35 mm rail.

If you are planning a cabinet from scratch, the 15 mm deep TS35 rail is worth considering for a computer: it is stiffer over the same fixing spacing and leaves a little more room behind the rail. Slotted rails make fixing easier; unslotted rails are stiffer and take self-tapping screws where you need them.

Following these points will see a DIN rail PC installed reliably in an industrial control cabinet or outdoor enclosure. Always check the manufacturer’s manual for the specific mounting instructions, power requirements and clearances for your model.

1. Choose the location. Pick a place on the rail with room for air around the computer and easy access to power and data cables, away from the hottest equipment in the cabinet.
2. Mount the rail. Fix a standard 35 mm rail horizontally or vertically, with fixings suited to the panel, so it cannot move or vibrate. Horizontal rails are the norm for computers, since they keep the fins vertical.
3. Prepare the computer. Fit the DIN clip or bracket if it is not already attached. Some clips are spring-loaded, others slide and lock with a screw.
4. Attach to the rail. Hook the top of the clip over the top edge of the rail and press the bottom until it snaps into place. You should hear or feel a click. Check by pulling gently.
5. Connect power. Most DIN rail PCs take DC through a terminal block, commonly from a 12, 24 or 48 V DC supply in the same cabinet. Confirm the voltage and current against the datasheet and tighten the terminals to avoid intermittent power.
6. Connect data and I/O. Ethernet, serial (RS-232 and RS-485), USB and digital I/O connect to the front panel. Use cable ties and strain relief so nothing pulls on the connectors.
7. Earth the computer. Connect the earth terminal, usually a screw or terminal-block pin, to the cabinet earth bar to control electrical noise and static discharge.
8. Check cooling. For a fanless model, make sure nothing obstructs the fins and that the manufacturer’s minimum clearances are met.
9. Power on and test. Watch the status LEDs and boot messages, test every connection and confirm the computer talks to the rest of the control system. Recheck the installation after the first period of operation.

Our guide to ways to mount an industrial computer compares DIN rail with wall, VESA and panel mounting, and for panels built to UL standards, UL 508A for control panels explains what the computer inside needs.

Most DIN rail clips release the same way. Insert a flat screwdriver into the slot or tab at the bottom of the clip, lever the spring latch down to free the lower edge, tilt the device away from the rail and lift it off the top edge. Disconnect power and cables first, and support the computer while you do it, since a heavier system will drop as soon as the latch releases.

Most DIN rail computers are fanless, and their fins pass heat to the cabinet air by natural convection. That only works if the warm air can rise away from the case and cooler air can reach it from below. A few rules keep a DIN rail PC within its rating.

• Fins vertical. Mount on a horizontal rail with the fins running up and down, as the manufacturer rates it.
• Space above and below. Leave the clearance in the manual, and keep cable ducts from closing off the top and bottom of the case.
• Not above hot equipment. Avoid mounting directly above drives, power supplies or transformers, which pre-heat the air reaching the fins.
• Rate to the cabinet air. The temperature that matters is inside the cabinet, often 10 to 20 °C above the room in a closed enclosure.

If the cabinet runs hot, our guide to electrical enclosure cooling works through the heat-load calculation and the cooling options, and how a fanless PC works explains why fin orientation matters. A processor that runs out of thermal margin slows down rather than failing, which our guide to thermal throttling describes, and installing an industrial fanless PC covers wiring and power in the cabinet.

A DIN rail clip is designed to hold a device against the rail, not to carry a heavy box on a shaking machine. Small DIN rail PCs typically weigh around a kilogram and sit happily on a single clip; larger box PCs with DIN kits can weigh two to four kilograms, and for those the maker’s own recommendation should decide between the rail and a wall bracket.

On machines and in vehicles, use end stops on both sides, fix the rail at closer spacing, and secure cables so their weight does not lever the computer off the rail. Where a computer is tested for vibration with a wall-mount kit, as the POC-915 is, that kit is the reference for harsh installations.

Industrial gateways and DIN rail computers are built for the conditions inside control cabinets and outdoor enclosures: temperature swings, dust, moisture, vibration and electrical noise.

• Rugged design. Most are fanless, which keeps dust and debris out, and built from metal that resists shock and vibration on factory floors and roadside sites.
• Compact and modular. Narrow cases sit between terminals and breakers, and the rail makes it easy to add, move or replace a computer later.
• Wide operating temperature. Many models run from −25 °C or −40 °C up to 70 °C, so they suit hot factories and unheated cabinets alike.
• Industrial I/O. Serial ports, multiple LAN ports, USB, isolated digital I/O and wireless let them connect sensors, actuators and controllers directly; our guide to DIO vs GPIO explains the digital I/O options.

For a recent example, the Neousys POC-900 brings AMD Ryzen AI to the DIN rail, with a 16 TOPS NPU in a 64 mm wide case. In practice, our IoT gateways monitoring manufacturing machines show DIN rail computers collecting machine data, and supercapacitor vs battery UPS explains how to keep a rail-mounted computer running through power dips.

These systems mount on the rail as standard or with a kit. We configure the operating system image, fit storage and wireless modules and test each computer before it ships.