Epson TM L90 Technical Reference Manual page 134

Note:
A signal name prefixed by "n" indicates an "L" active signal.
Bidirectional communications cannot take place unless all signal names for both sides correspond to each
other.
Connect all signal lines using twisted pair cables. Connect the return side to the signal ground level.
Make sure that the signals satisfy electrical characteristics.
Set the leading edge and trailing edge times to 0.5 µs or less.
Do not ignore nAck or BUSY signals during a data transfer. Ignoring such signals may result in data
corruption.
Make the interface cables as short as possible.
Rev. B
A-6 Interface And Connectors