User’s Guide
B.Interface Specifications
B.1 Parallel Interface
∙Data Transmissions:
7 or 8 bit
∙Synchronization:
Externally supplied Data Strobe
∙Handshaking:
Acknowledge (Busy before Acknowledge or Busy after Acknowledge) Busy (Acknowledge before Busy or Acknowledge after Busy)
∙Logic Level:
Input data and all interface signals are TTL compatible.
Two output signals control the handshaking on the parallel interface, the BUSY signal and the ACKNOWLEDGE signal. An incoming DATA STROBE will cause BUSY to go high.
PAPER END: | The PAPER END signal is an active high signal that will go high |
| when paper out is detected. |
ERROR: | The ERROR signal will go low with the detection of an error |
| condition. A fatal printer error condition exists when ERROR is low, |
| PAPER END is low and SELECT is high. |
SELECT: | When the printer is ready to receive data, the SELECT signal is set |
| high. This signal will go low when: |
| The On/Off Line key is pressed. |
| There is a carriage jam. |
| Paper out is detected. |
| Fatal errors. |
Interface Specifications