The prevention of an unexpected start-up

Posted to News on 11th May 2026, 11:00

The prevention of an unexpected start-up

For many years, safety devices, safety relays, PLCs have worked harmoniously to provide a safe working environment for man and machine. As machines have developed over the years, so have the safety standards and safety devices that guard them.

In today's modern age, companies demand speed, excellence and safety for their workers and machines to provide the best quality products with the least downtime. This can be a challenging concept when trying to keep production at a high output and maintain the safety of the employees.

When a machine requires attention, an operator would access the machine to solve the problem at hand. To prevent the machine from being started while the operator is inside the machine (unexpected start up according to ISO14118), some companies adopt a LOTO (lockout/Tagout) policy to ensure the safety of their operators.

This can be a time consuming process with adding and removing locks from doors or energy sources.

The safety standard ISO 14118 specifies requirements for designed-in means aimed at preventing unexpected machine start-up to allow safe human interventions in danger zones. This is why Mechan Controls has designed the Nota range, a keyless "tag in/ tag out" system that prevents the machine from being started until designated user(s) have safely left the dangerous zone.

The Nota range has a 4 billion unique codes for a high level of coding, according to ISO 14119. Each Nota station can accept up to 20 operators with their own individual tags.

With advanced LED indication, the Nota range aims to make entering and exiting a machine area as simple and as safe as possible.

Adding or removing users has never been more simple, no need to send the Nota unit back to be re-programmed. The master key holds all the functions to remove and add operators to the Nota device.

Finally, to make the Nota range compatible with numerous safety relays and PLCs in the market, Mechan has designed two versions: one with standard MOSFET relay outputs to work with the large range of safety relays that only accept MOSFET inputs; and one with OSSD outputs for more advanced safety relays or PLCs that require pulsed (OSSD) signals.

The Nota range is a unique product available in ABS or 316 Stainless Steel exclusive to Mechan Controls.

1 / 2