What is the difference between an IRIG-B time display and an NTP time display?

An IRIG-B display reads time from a differential pulse signal wired directly from a master clock, while an NTP display pulls time over the plant Ethernet network. IRIG-B suits control rooms and OT networks that are isolated from IT infrastructure, where an NTP display would have nothing to connect to.

How many IRIG-B slave displays can run on one master clock?

Up to 300 slave display units can be connected to a single master clock on a shared multi-drop bus, covering a plant area with a radius of up to 1 km. Larger deployments use distribution units with signal boosters to extend the reach further.

What happens if one slave display unit fails?

The multi-drop network is fault isolated, so a failed display has no effect on any other unit sharing the bus. The faulty unit can be replaced or repaired without interrupting the time display anywhere else on site.

Can the IRIG-B Time Display 100mm be installed outdoors?

Yes. The display carries IP55 protection as standard and is available in an IP66 rated version for outdoor installation, with an operating range of minus 10 to plus 85 degrees Celsius.

Can the time format be changed from HH:MM:SS to HH:MM?

Yes. The display ships in HH:MM:SS format by default, with HH:MM format and other output options available on request to match project specifications.

Digital Display

IRIG-B Time Display 100mm

Name: IRIG - B Time Display 100mm (T-SL-300-100-6D)
Brand: Sertel

T-SL-300-100-6D

A 100mm LED slave clock built to run off an IRIG-B or differential pulse signal, so control rooms, switchyards and test facilities keep one second-accurate time reference even on networks with no Ethernet or NTP infrastructure. Wired into a multi-drop bus from a central master clock, it displays hours, minutes and seconds on a large red 7-segment face, visible across a control room or along a shop floor.

Reads time directly from an IRIG-B / differential pulse signal, no network required

Multi-drop bus supports up to 300 slave units from a single master clock

IP55 weatherproof as standard, IP66 available for outdoor installation

Universal 90 to 260V AC/DC power input

View Specifications

Sertel T-SL-300-100-6D IRIG-B slave clock display with 100 mm red LED digits

Key Advantages

Built for Plants Where Network Time Cannot Reach

Most industrial sites run two separate networks: an IT network carrying email and business applications, and an OT network running the switchgear, protection relays and SCADA systems that keep the plant online. IRIG-B was built for the second kind of network. It carries time as a differential pulse rather than as data packets, so a slave display can decode it without an IP address, a switch port or a working NTP service nearby. For sites where the control network is intentionally isolated from the corporate LAN, that is not a limitation. It is the point.

Differential Pulse / IRIG-B Signal Input

The display decodes hour, minute and second data straight from the IRIG-B or differential pulse feed sent out by the master clock. There is no protocol stack to configure and no dependency on switch uptime, so the displayed time stays locked to the master clock for as long as the signal cable stays connected.

Multi-Drop Bus Architecture

All slave displays share a single common bus running from the master clock, so a new unit is added by tapping into the existing run rather than pulling a dedicated cable back to source. Wiring a control room or a line of switchyard bays takes one cable path instead of one cable per display.

Up to 300 Units on One Master Clock

A single master clock can drive up to 300 slave display units across a plant area with a 1 km radius, enough reach for a large substation, a manufacturing floor or a multi-building campus to show one time from one source.

Fault-Isolated by Design

Because every unit reads the same bus independently, the failure of one display has no effect on any other unit on the network. A faulty display can be pulled for service without taking down time reference anywhere else on the site.

100mm Red LED, 7-Segment Display

Hours, minutes and seconds are shown as two-digit 7-segment numerals, 100mm tall and customisable where a project calls for a different size, in 12 or 24-hour HH:MM:SS format, with HH:MM available on request. The display refreshes every second so it stays in step with the master clock at all times.

Wide-Angle Red Filter

A red transparent filter overlay widens the viewing angle and keeps the digits legible from the side as well as head on, under the fluorescent, sodium vapour or daylight conditions typical of control rooms and outdoor yards.

IP55 Standard, IP66 for Outdoor Use

The enclosure meets IP55 protection as standard, with an IP66 rated version available for displays mounted outdoors or in washdown areas, and is rated for ambient temperatures from minus 10 to plus 85 degrees Celsius and up to 90 percent relative humidity, non-condensing.

Universal Power Input

A 90 to 260V AC/DC power input lets the same unit run across plants with different supply standards, without a separate transformer or power module per site.

Applications

Used Across Critical Environments

IRIG-B displays are specified wherever a facility needs one trusted time source distributed to many screens, and where that source cannot depend on the plant's IT network staying up. The applications below reflect where that requirement shows up most often.

Power Generation, Transmission and Distribution

Defence and Aerospace Test Facilities

Telecom Exchanges and Network Operations Centres

Railways and Metro Signalling

Process Plants and Marine Control Rooms

Technical Specifications