Epson TM-T60/T60P Operator's Manual page 76

NOTES: 1. For interface wiring, be sure to use a twisted-pair cable for each
side and connect the return side to the signal GND level.
To prevent noise, these cables should be shielded and con
nected to the chassis of the host computer.
2. Ail of the interface conditions are based on TTL levels.
The rising time and falling time of any signal should be 0.2 µs or
less.
3. Never transmit data without checking ACKNLG and BUSY.
(Data should only be transmitted to this printer after confirming that
ACKNLG is active, or when BUSY is "LOW".)
4. The interface cable should be as short as possible.
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