JMRI: Fast Clock - Setup
Author: Bob Jacobsen
Keywords: JMRI help Setup Fast Clock

# JMRI: Fast Clocks

JMRI provides two kinds of Fast Clock capability:

- Internal - the computers clock provides the time information
- External - the DCC system ( or an object on a Layout Control Bus ) provides the time information

This help page describes the overall structure.

There are two different parts to consider: A "Timebase" provides the basic time information, while one or more displays show you what's going on.

## Fast Clock Timebase

To create a Timebase, use PanelPro > Tools > Clocks > Set up Fast Clock... This gives you a window where you can:

- Set the time
- Start and stop the clock
- Set the rate at which the clock runs
- Select the timebase source to control (typically, this is the internal computer clock)

## Fast Clock Display

Once you have created a timebase by configuring it in that window, you can open clocks that will display on your screen, all with an optional pause/run button.

All clocks can be resized by dragging the window edges

- Tools > Clocks > Analog clock - The traditional circular clock with hands.

- Tools > Clocks > LCD clock - a digital clock.

- Tools > Clocks > Nixie clock - a digital clock that looks like the old-style Nixie tubes

- Tools > Clocks > Pragotron clock - flip clock used in net Czechoslovak State Railways – ČSD since 4.19.2

- Panel clock - you can also embed a clock in a panel from the panel editor.
  Analog clocks can be embedded into Layout Editor panels (instead of a separate window) via Panel Window > Options > Add > Add Fast Clock

When a clock is running, JMRI creates an internal sensor and a memory variable that you can use to control and access the clock. The ISCLOCKRUNNING sensor controls whether the clock is running (ACTIVE) or stopped (INACTIVE). The IMCURRENTTIME memory contains the current fast-clock time, and can be easily accessed from Logix and scripts.

Lights can be an easy way to set up Fast Clock Logic, see Light Controller - Fast Clock Follower.

Fast Clock Setup

Happy timekeeping!