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Your first alarm ​

Run a small IOC on your own computer, raise an alarm, and acknowledge it in QtALH. You will see the difference between a current alarm and an alarm that still needs acknowledgement.

Before you begin: build QtALH and EPICS Base. You need a desktop session and the Base tools softIoc and caput. The walkthrough below uses a Linux/macOS shell, two terminals, and the repository's tutorial database and configuration.

1. Set up a local connection ​

Open two terminals at the repository root. Run the following in both terminals. Replace the Base path and host architecture to match your installation; on macOS, for example, the host architecture may be darwin-aarch64.

sh
export PATH=/path/to/base/bin/linux-x86_64:$PATH
export EPICS_CA_AUTO_ADDR_LIST=NO
export EPICS_CA_ADDR_LIST=127.0.0.1:5068
export EPICS_CA_SERVER_PORT=5068
export EPICS_CA_REPEATER_PORT=5069
export EPICS_CAS_INTF_ADDR_LIST=127.0.0.1
export EPICS_CAS_BEACON_ADDR_LIST=127.0.0.1:5069

These settings keep this exercise on loopback and use a separate pair of CA ports. If those ports are already in use, choose another unused pair and update both terminals consistently. The variables apply to the current terminals only.

2. Start the IOC ​

In the first terminal:

sh
softIoc -d examples/tutorial.db

Expected result: the IOC starts and presents an epics> prompt. Leave it running. The pressure record starts at zero, with no active alarm.

3. Open QtALH ​

In the second terminal:

sh
bin/Linux-x86_64/qtalh --validate examples/tutorial.alhConfig
bin/Linux-x86_64/qtalh -D -s -mainwindow examples/tutorial.alhConfig &

On Apple Silicon, substitute bin/Darwin-arm64/qtalh. Validation should report 1 channel and 2 groups. In the main window, select Vacuum and find Vacuum pressure. After connecting, it should be normal.

This exercise uses default local acknowledgement, disables file logging (-D), and silences audio (-s). It leaves acknowledgement enabled. If the row stays ERROR, check that the IOC is running and both terminals have the same CA settings.

To use modern controls and layouts, add -style fusion to the launch command. The default remains the familiar Motif appearance; -style motif selects it explicitly. Both appearances provide the same alarm actions.

QtALH with Fusion styling

4. Raise and clear the alarm ​

Run each command in the second terminal and observe the row before continuing:

sh
caput qtalh_demo:pressure 7

The channel enters MINOR, with a yellow alarm indicator. Its parent group reflects the alarm.

sh
caput qtalh_demo:pressure 12

The channel enters MAJOR, with a red alarm indicator.

sh
caput qtalh_demo:pressure 0

The active severity returns to NO_ALARM. With the default mask, the highest unacknowledged transient remains until you acknowledge it.

5. Acknowledge the channel ​

Select Vacuum pressure, then use Action → Acknowledge Alarm or Ctrl+A. The outstanding acknowledgement clears. Acknowledgement records that an operator has seen an alarm; it does not change the pressure PV or correct the underlying condition.

Hover over the channel's G button to preview its guidance without opening a dialog. Open the guidance using G or Ctrl+G. The instructions are stored in the configuration's $GUIDANCE block.

6. Finish the exercise ​

Close the compact QtALH window and confirm exit. In the IOC terminal, enter exit at the epics> prompt. Close the two terminals to discard their temporary environment settings.

Next, create your own configuration or compare local, global, and passive modes.