Epson TM-L90 Developer's Manual page 52

Confidential
J Power off procedure
1. Transmit the last printing command (LF, ESC d , etc.).
2. Transmit GS ( D pL pH m a b (pL = 3, pH = 0, m = 20, a = 2, b = 1).
3. Transmit GS r n (n = 1).
4. Wait for transmission of paper detector status from printer by GS r n.
5. Transmit DLE DC4 n a b (n = 2, a = 1, b = 8).
6. Wait for transmission of power supply off status.
Note:
Within 10 seconds after transmitting DLE DC4 n a b, power supply off procedure is carried out and
power supply off status is transmitted.
7. If power supply off status is not confirmed, wait 10 seconds or more after transmitting DLE
DC4 n a b.
Note:
Process varies according to interface.
Interface
Serial interface
Parallel interface
8. At this time, internal process is being carried out in the printer by software.
9. After processing;
a. When the power switch is enabled, the printer turns off.
b. When the power switch is disabled, the POWER LED blinks and the printer is in the
waiting sate.
After confirming that, turn off the power breaker or the outlet.
Note:
Do not reset the printer during the period before turning off the power supply of the printer and after
transmitting DLE DC4 (n=2) command.
Rev. A
Countermeasure
Status is transmitted regardless of the state of host.
Carry out negotiation as soon as transmitting DLE DC4 n a b
so that status from printer can be received.
TM-L90 Developer's Guide
Description of Functions 3-3