Configuring Abel to use bell sensors

If you are using Abel with externally connected bells, you must tell Abel how they are connected before it will recognise them. To do this, click on the Options menu item and then on External Bells. The following dialog will be displayed:

The purpose of this dialog is to tell Abel which external bells are connected to which serial ports of the computer, and what types of signal they will send to that serial port. You can specify up to 16 external bells using this dialog.

For each bell you want to connect to Abel:

Note. The mapped bell numbers do not refer to the numerical values of Abel's bells - so if you have an external bell mapped to bell number 1, this does not mean that external bell is always going to ring as the Treble in Abel. The mappings refer to the manual bells i.e. the bells you select as being the ones you actually ring. So, if you have only one external bell connected to Abel, configure this to map to bell number 1. Then, when you select a method to ring, you can choose to ring the 4th or the tenor if you like, without having to change configurations. Similarly, if you have 6 bells connected, configure them as bells 1-6, not as bells 11-16. And if you're using David Bagley's Multi-Bell Interface, again you must use the lowest numbered bells.

Now you need to tell Abel how many signals to expect for each strike of the bell.

If you are using serial line control signals, Abel detects signal transitions. So, for example, if you are using optical sensors with two reflectors on the wheel (see Optical Sensor Design), Abel will receive two signals (on and off) as each reflector passes the sensor head – four signals in all. In this instance, with the reflectors positioned as shown in the diagram in Optical Sensor Design, you actually want Abel to ring the bell as it receives the third of these signals (that is, the 'on' signal as the bell approaches the end of its rotation). To do this, set Control Signals so that it says "Ring on 3 of 4".

If you are using a Multi Bell Interface, then you can give similar information in the Data Signals box. However, the current design of Interface sends only a single signal each time the bell strikes. Therefore you should leave the setting as "Ring on 1 of 1". You don't need to do anything else to use the Interface – so long as you configure your external bells starting at ‘1', Abel knows what signals to expect.

Debounce bells/switches

This control lets you choose a debounce period, in milliseconds. This is useful if you have simple mechanical switches for your external bells or controls, since Abel will ignore signals that arrive within this configured number of milliseconds. The maximum value is 100 milliseconds and the default value 20 milliseconds, though these figures are rather approximate. If you find that your bells ring several times instead of just once when you use external bells, you can try increasing the debounce period.

Clear mappings

This button will clear all the mappings, blanking all the Map to boxes, so that you can choose again how you relate external bells to Abel's bells. It does not clear the details of control signals, or the "Ring on x of y" settings.

Reset 1:1 mappings

This button sets all the mappings for you. External bell 1 will be mapped to Abel's first manual bell, external bell 2 to Abel's second manual bell, etc. This is normally what you require.


David Bagley's Multi-Bell Interface is designed to detect when a turning bell passes bottom-dead-centre, and then send a signal to Abel after a fixed time. You have to tell Abel how long this time should be, for each bell, and Abel will send this information to the Interface when you click the OK button on the External Bells dialog. Similarly, if you connect a sensor with a single bottom-dead-centre activator to one of the PC's COM port control signals, Abel can apply an appropriate fixed delay to the signal. In either case, you click on the Sensor Delays button, and a new dialog will appear.

If you are using a single bottom-dead-centre activator for each sensor, and not using a Multi-Bell Interface, click the box "Apply Delays in Software for Control Signals".

After you have set the delays, click on Apply to make the changed values take effect immediately and return you to this dialog, or click on OK to return to the External Bells dialog. Any changed values will also be sent when you click the OK button on the External Bells dialog.

You don't need to use this Delays dialog if you are not using sensors with a single activator.

Saving options

When you have finished configuring your external bells, click on OK on the External Bells dialog. Now click on the Options menu item and then Save Options to save your settings in the current options file (or Save Options As… if you want to save to a different file).

See also:

  Connecting external bells
  Configuring Abel to use control switches
  Debugging external connections