APPENDIX 2 Parallel Interface
Both the
(1) Specifications |
|
|
|
|
| |
(a) | Data transfer rate: | 1000 CPS (min.) |
|
| ||
(b) | Synchronization: | By externally supplied STROBE pulses. | ||||
|
|
|
|
| ||
(c) | Handshaking: | By ACKN LG or BUSY signals. | ||||
(d) | Logic level: | Input data and all interface control signals are | ||||
|
| compatible with the TTL level. |
(2) Connector
Plug:
It is recommended that interface cables be kept as short as possible.
(3) Connector pin assignment and descriptions of signals.
Connector pin assignment and descriptions of respective interface signals are provided in Table
STROBE pulse to read data in. Pulse width must be more than 0.5µs at receiving terminal.
The signal level is normally “HIGH”; read- in of data is performed at the “LOW” level of this signal.
These signals represent information of the 1st to 8th bits of parallel data respectively. Each signal is at “HIGH” level when data is logical “I” and “LOW” when logical “0”.
Approx. 5µs pulse. "LOW" indicates that
data has been received and that the printer
i s r e a d y t o a c c e p t o t h e r d a t a .
A "HIGH" signal indicates that the printer
cannot receive data. The signal becomes “HIGH” in the following cases:
1. During data entry
2. During printing operation
3. In
4. During printer error status.
A “HIGH” signal indicates that the printer is out of paper.
- 8 7 -