LTSC

LTSC is useful for interfacing lighted pushbuttons. It contains both - inputs for switches, and outputs for direct LED drive. The inputs work exactly like any other BBS-type scanner, meaning when you press the button, typically a note-on will be sent. Releasing the contact will cause a note-off message to be sent. So just like any keyboard. On the other hand the LED outputs work like MIDI note decoder, for example MIDECO board. But here inputs and outputs are interlaced so wiring a set of lighted buttons seems to be easier and more logical.
The board has 4 black connectors for user devices. Each of them covers 8 pairs of button+LED according to the following schematic:

This board was made to replace LITSW controller, which was released 15 years ago and still being in high demand. LTSC adds daisy chain input and 4th header for buttons, not to mention regular screw terminal for the common wire of all LEDs and switches. It is not however a direct replacement. LITSW had quite a few features like button dependencies, split, cancel mode, CC-mode, bank/select mode and others, while lacking the ability to send any MIDI on button release (difficult to use it as SET piston in organ consoles), and no daisy chain input. Nevertheless all those special features were rarely used, maybe 5% of customers needed them. LITSW is still available in special cases like that. But in most typical use, where LTSC is taking care of lighted buttons where all lights are controlled via MIDI by Hauptwerk software or similar, this is all you'll ever need.

Features:

scans 32 contacts
drives 32 LEDS directly at about 3mA
daisy chain input, up to 4 LTSC on a single chain
LEDs are controlled only by incoming MIDI
dimensions: 86x55mm
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