2-3. Connectors and Signals
RS-232C
Pin no. | Signal name | I/O | Function | |||
direction | ||||||
|
|
|
|
| ||
1 |
| — | Frame ground | |||
2 |
| TXD | OUT | Transmitted data | ||
3 |
| RXD | IN | Received data | ||
4 |
| RTS | OUT | Data transmission request signal. This is al- | ||
|
|
|
|
| ways “SPACE” when the printer is turned on. | |
5 |
| CTS | IN | This signal changes to “SPACE” when | ||
|
|
|
|
| host computer is ready to transmit data. (In | |
|
|
|
|
| this instance, the printer does not check this | |
|
|
|
|
| signal.) | |
6 |
| N/C |
| Not connected | ||
7 |
| — | Signal ground | |||
8 |
| N/C |
| Not connected | ||
| N/C |
| This pin is used when using the optional | |||
|
|
|
|
| interface board. | |
11 |
| RCH | OUT | This signal changes to “SPACE” when the | ||
|
|
|
|
| printer is ready to receive data. (The signal | |
|
|
|
|
| line is same as pin 20.) | |
12 |
| N/C |
| Not connected. | ||
13 |
| — | Signal ground | |||
14 |
|
|
| OUT | When printer error occurs (such as paper | |
| FAULT | |||||
|
|
|
|
| out, mechanical error, etc.), this signal is | |
|
|
|
|
| set to “MARK”. | |
15 | OUT | Diode coupled TXD | ||||
16 | OUT | Diode coupled DTR | ||||
17 to 19 |
| N/C |
| This pin is used when using the optional | ||
|
|
|
|
| interface board. | |
20 |
| DTR | OUT | Data terminal ready signal. When the printer | ||
|
|
|
|
| is ready to receive data, this signal changes | |
|
|
|
|
| to “SPACE”. | |
| N/C |
| Not connected | |||
23 to 25 |
| N/C |
| This pin is used when using the optional | ||
|
|
|
|
| interface board. | |
| 14 |
|
| 25 | ||
| 1 |
|
| 13 | ||
Fig. 2-4 Serial interface connector
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