Epson EPL-5000 Guide De L'utilisateur page 648

Note:
All interface conditions are based on TTL level. Both the rise and fall times
of each signal must be less than 0.2 microseconds.
Data transfer must be carried out by observing the ACKNLG or BUSY
signal. (Data transfer to this printer can be carried out only after receipt of
the ACKNLG signal or when the level of the BUSY signal is LOW.)
The column heading "Direction" refers to the direction of signal flow as
viewed from the printer.
Return denotes the twisted-pair return to be connected at signal ground
level. For the interface wiring, be sure to use a twisted-pair cable for each
signal and to complete the connection on the return side.
The ACKNLG pulse width varies.
To enable bidirectional parallel interface communications between the printer and
computer, set the connector pin assignments as follows:
Technical Specifications
A-7