Alarm devices

Drive a signal light or a beeper from the robot state, for example steady green while engaged and blinking red after an error.

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The alarm devices turn a number, normally the robot state, into on and off signals for a signal light or a beeper. There are two of them, Beeper and Light, and they work the same way. Out of the box they are linked to the robot state, but every output is 0: you choose what each state looks or sounds like.

Input: the robot state Robot state root/Logic/state root/AlarmDevices/Light Sequencer01: ids 4: engaged, steady green Sequencer01 ids 4: engaged, steady green Sequencer02: ids 6, 7: error, blinking red Sequencer02 ids 6, 7: error, blinking red Sequencer03: ids -1: not used Sequencer03 ids -1: not used Sequencer04: ids -1: not used Sequencer04 ids -1: not used Sequencer05: ids -1: not used Sequencer05 ids -1: not used defaultOutput: when no ids match defaultOutput when no ids match output 3 channels Output: to digital outputs Digital outputs lamp or beeper

How it works

Each device has five sequencers, Sequencer01 to Sequencer05, and three output channels. Every control cycle:

  • The device writes defaultOutput to output.
  • Each sequencer compares the input with its ids. A sequencer with a match plays its sequence and writes it to output, instead of defaultOutput.
  • If more than one sequencer matches, the one with the highest number wins.
  • A sequencer without a match stops and starts from the beginning the next time it matches.

Choose the input

In the standard configuration, the group From Logic To Alarm in linking/base.link.json links the robot state to both devices:

{
  "Name": "From Logic To Alarm",
  "SystemMode": "All",
  "Enable": true,
  "Links": [
    { "Source": { "Path": "root/Logic/state" }, "Destination": { "Path": "root/AlarmDevices/Beeper/input" } },
    { "Source": { "Path": "root/Logic/state" }, "Destination": { "Path": "root/AlarmDevices/Light/input" } }
  ]
}

These are the values of root/Logic/state you can use as ids:

State Value Drives
INIT_S 0 Off, while the application starts
OFF_S 1 Off
IDLE_S 2 On
ENGAGED_S 4 On, the robot can move
HOMING_S 5 On, the robot is homing
FORCEDIDLE_S 6 On, stopped after an error
ESTOP_OFF_S 7 Off, after an emergency stop
Transition values

Between two states, root/Logic/state briefly holds a transition value. They last only as long as the transition, so they are rarely useful as ids.

Transition Value
OFF_TO_IDLE_T 102
IDLE_TO_OFF_T 201
IDLE_TO_ENGAGED_T 204
PAUSED_TO_IDLE_T 302
ENGAGED_TO_PAUSED_T 403
TO_FORCEDIDLE_T 600
RESET_FORCEDIDLE_T 602
TO_ESTOP_T 700
RESET_ESTOP_T 701

To drive a device from something else, change the Source of its link, for example to one of your own user parameters. See link files.

Set a sequence

A sequence has five steps. Each step sets all three channels for a time, and the sequence then loops for as long as the input matches. The parameters are under root/AlarmDevices/Light/ or root/AlarmDevices/Beeper/:

Parameter What it does Standard configuration
defaultOutput The value of the three channels when no sequencer matches 0 0 0
SequencerNN/ids Up to three input values that start this sequencer. -1 means not used -1 -1 -1
SequencerNN/durations How long each of the five steps lasts, in s 0 0 0 0 0
SequencerNN/channel_01 to channel_03 The value of output[0] to output[2] in each of the five steps 0 0 0 0 0
output Output: the three channels, to link to your lamps or beeper

Which channel is which colour depends on how you wire the outputs. The example below blinks output[0], for example a red lamp, at 1 Hz:

What you set durations channel_01 step 1 0.5 s 1 step 2 0.5 s 0 step 3 0 s 0 step 4 0 s 0 step 5 0 s 0 duration 0: each lasts only one control cycle What you get output[0] 1 0 step 1 step 2 step 1 step 2 0 s 0.5 s 1 s 1.5 s 2 s steps 3 to 5 pass here, too short to see; then step 1 starts again

A step with duration 0 still lasts one control cycle. For a pattern with fewer than five steps, give the extra steps duration 0 and the same values as the step before them, so they do not cause a short flash.

Example: a signal light

With output[0] wired to a red lamp and output[1] to a green lamp, these settings give steady green while the robot is engaged, and blinking red after an error or an emergency stop:

Parameter Value Why
Sequencer01/ids 4 -1 -1 Engaged
Sequencer01/channel_02 1 1 1 1 1 Green on in every step
Sequencer01/durations 1 1 1 1 1 Any value works for a steady light
Sequencer02/ids 6 7 -1 Forced idle or emergency stop
Sequencer02/channel_01 1 0 0 0 0 Red on, then off
Sequencer02/durations 0.5 0.5 0 0 0 0.5 s on, 0.5 s off

Set the values in Motorcortex Desk and save the parameter tree to keep them.

What this looks like in Motorcortex Desk

A sequencer that blinks output[0] while the input is 1: channel_01 is 1 0 0 0 0 and durations is 1 1 0 0 0.

Motorcortex Desk: a sequencer with channel_01 1 0 0 0 0, durations 1 1 0 0 0 and ids 1 -1 -1. With input 1, output ch0 switches between 1 and 0 every second in the plot.

output is not linked to any hardware in the standard configuration. Link it to a digital output of an EtherCAT I/O module in the ECAT tool: open the module’s rxPDO tab, find the output channel and link it to root/AlarmDevices/Light/output. The channel number picks the element: channel 0 is output[0]. See Digital I/O for adding and linking an I/O module.

Check it

  1. Deploy the configuration and open Motorcortex Desk.
  2. Switch the robot between off, idle and engaged, and watch root/AlarmDevices/Light/output change with the state.
  3. On the real machine, check that each lamp and the beeper follow the output.

Next: Step 6: add a 3D model.