The keyboard decoder`s electronic system recognizes keystrokes at the decoder`s matrix inputs. The decoder converts these keystrokes into key-codes which - depending on the required interface - are transferred to the connected unit in the form of an electrical signal. More keys can be queried via the matrix assignment and using the same number of wires. The decoders are distinguished by a series of common characteristics:

FTDK...301/302/56: Keypad connection: 2 x 8-pole direct plug for front membrane, or for FTDK 56 8 x 13-pole direct plug for membrane strip conductor
Computer connection: 8-pole pin bar, single row
Dimensions: 78 x 84 x 16 mmInterfaces: IBM standard AT, PS/2, V24 ( RS 232 ), 20 mA current loop ( passive ), TTL level
Supply voltage: XT, AT, PS/2:5 V, 120 mA, V24 ( RS 232 ), 20 mA current loop, TTL level: 5 V, 150 mA
Buzzer: Built-in beeper generates a click sound when a key is pressed
FTDK...90/102:Keypad connection: 2 x 16-pole direct plug for membrane cable
Computer connection: 8-pole pin bar, single row
Dimensions: 100 x 117 x 16 mmInterfaces: IBM standard AT, PS/2 ( switchable ), V24 ( RS 232 ), 20 mA current loop ( passive ), TTL levelSupply voltage: XT, AT, PS/2:5 V, 120 mA, V 24 ( RS 232 ), 20 mA current loop, TTL level:5 V, 150 mABuzzer: Built-in beeper generates a click soung when a key is pressed