Choosing the Right Splice Mode on Your Fusion Splicer

A fusion splicer does not use one fixed setting for every fibre. Each fusion splicer splice mode, sometimes called a splice programme, sets the arc power, arc times, gap and other parameters the splicer uses. Choosing the right one is one of the simplest ways to get low, consistent splice loss.

This guide explains the main splice modes on INNO fusion splicers, when to use each one and how to change the mode in a few seconds.

The main splice modes

Auto mode

In Auto mode the splicer identifies the fibre type, such as single-mode (SM), multimode (MM) or dispersion-shifted (DS), and adjusts the arc power and timings to suit. It is the quickest and simplest option.

• ideal for technicians who are new to splicing
• suited to high-volume work where speed matters
• reliable under standard conditions with common fibre types

Manual mode

Manual mode gives you full control over the splicing parameters, including arc intensity, arc time and alignment settings.

• specialist installations that need non-standard settings
• repair work and checking splicer performance
• unusual fibre types or test set-ups

Single-mode (SM) mode

This programme is optimised for single-mode fibre, which has a small core of around 9 microns. It is the mode most UK telecoms work relies on, from backbone routes to FTTP drops.

• long-distance and backbone networks
• access and FTTP networks
• any link where low loss is critical

Multimode (MM) mode

Multimode fibre has a much larger core, typically 50 or 62.5 microns, and needs different arc settings to splice well.

• local area networks inside buildings and campuses
• data centres and other short-reach links

Quick guide to choosing a mode

How to change the splice mode on an INNO splicer

Step 1. Check the active mode

The current splice mode is always shown on the left side of the screen, so you can confirm it before you start.

Step 2. Open the splice mode list

Select [Splice Mode] from the main menu. The splicer lists the available modes, including Auto, Manual, Single Mode and Multimode.

Step 3. Select the mode

Highlight the mode that matches your fibre, for example Single Mode for SM fibre or Multimode for MM fibre, and select it.

Step 4. Return to splicing

The selected mode now appears on screen. Press [Reset] to return to the main splicing screen and carry on.

Custom programmes for unusual fibre

Some jobs involve fibre with unusual coatings, diameters or specifications. In these cases you can adjust parameters such as arc current, test the result and save the settings as a custom programme. Once saved, the programme can be selected in seconds next time, which keeps results consistent across the team.

If you change parameters, change one at a time and make a test splice after each change. That way you know which setting made the difference.

Still seeing errors?

If the right mode is selected and splices still fail, the cause is usually preparation, electrodes or arc calibration. Our guide to fusion splicing problems covers the most common errors and how to fix them. When the problem is the splicer itself, our UK service and repair centre turns most repairs round in 3 working days.

Choosing a new splicer? Our guide to core alignment vs cladding alignment explains which type suits your work, and you can browse our fusion splicers, all held in UK stock. For advice on settings for a particular fibre, contact our technical team.