DR300 Operator Manual | Chapter 10 - Serial Interface |
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Ready/Busy
This is the hardware flow control for the serial interface on the DR printers. By raising/lowering the voltage level on Pin 20 of the RS232 port, the printer notifies the host when it is ready to receive data. Pin 40 (RS) and Pin 20 (DR) are the important signals on the printer for this method of flow control. The host must be capable of supporting this flow control method for it to function properly. The selection of 1 item or multi items print buffer can be set by DIP switch.
Data stream (ESC + “A” ~ ESC + “Z”) from host might not be fully received by printer under the following conditions:
•Printer is in printing process during Single Job Buffer Mode.
•Printer is engaged with error condition.
1 : Cable connection |
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Host | Printer | |
FG |
| 1 FG |
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RD | 2 SD | |
SD | 3 RD | |
CS | 4 RS | |
RS | 5 CS | |
ER | 6 DR | |
SG |
| 7 SG |
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DR | 20 ER | |
2 : Input/Output signal explanation
Pin No. | Signal | Direction | Content |
| Name |
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1 | F G | - | Frame ground |
2 | S D | Output | Data transmitted from printer to host |
3 | R D | Input | Data transmitted from host to printer |
4 | R S | Output | “Low” level when error occurs in printer |
5 | C S | Input | Always hold “High” |
6 | D R | Input | Always hold “High” |
7 | S G | - | Signal ground |
20 | E R | Output | “High” when printer is ready to receive data |
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| “Low” when various errors occur, when the printer is |
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| offline, and while printing in the Single Job Buffer |
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| Mode. It will also go “Low” when the data in the |
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| buffer reaches the Buffer Near Fall Level |
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