2.9 Connection of Peripherals
For connecting a printer/PC with a 25-pin RS-232C connector
Hybrid
Circuit Type | Signal | Pin No. | |
(EIA) | Name | ||
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BB | RD (RXD) | 2 | |
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BA | SD (TXD) | 3 | |
CD | ER (DTR) | 4 | |
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AB | SG | 5 | |
CC | DR (DSR) | 6 | |
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CA | RS (RTS) | 7 | |
CB | CS (CTS) | 8 | |
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RS-232C Signals
Printer/PC
Pin No. | Signal | Circuit Type | |
Name | (EIA) | ||
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1 | FG | AA | |
3 | RD (RXD) | BB | |
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2 | SD (TXD) | BA | |
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20 | ER (DTR) | CD | |
7 | SG | AB | |
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5 | CS (CTS) | CB | |
6 | DR (DSR) | CC | |
4 | RS (RTS) | CF | |
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•Receive Data (RXD):…(input)
Conveys signals from the printer or the PC.
•Transmit Data (TXD):…(output)
Conveys signals from the unit to the printer or the PC. A "Mark" condition is held unless data or BREAK signals are being transmitted.
•Data Terminal Ready (DTR):…(output)
This signal line is turned ON by the unit to indicate that it is ON LINE. Circuit ER (DTR) ON does not indicate that communication has been established with the printer or the PC. It is switched OFF when the unit is OFF LINE.
•Signal Ground (SG)
Connects to the DC ground of the unit for all interface signals.
•Data Set Ready (DSR):…(input)
An ON condition of circuit DR (DSR) indicates the printer or the PC is ready. Circuit DR (DSR) ON does not indicate that communication has been established with the printer or the PC.
•Request To Send (RTS):…(output)
This lead is held ON whenever DR (DSR) is ON.
•Clear To Send (CTS):…(input)
An ON condition of circuit CS (CTS) indicates that the printer or the PC is ready to receive data from the unit. The unit does not attempt to transfer data or receive data when circuit CS (CTS) is OFF.
•Frame Ground (FG)
Connects to the unit frame and the earth ground conductor of the AC power cord.
