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| Appendix F - Pin Descriptions |
Label | Pin | I/O type | Signal name/description |
RDL | 21 | RDL | Remote Digital Loop Input to modem to enable RDL test. |
RI | 22 |
| Ring Indicator RI output high indicates the presence of |
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| a ring signal on the telephone line. |
| 23 |
| NC |
XCLK | 24 | XCLK | External Clock Input to modem used in special syn- |
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| chronous applications. |
TM | 25 | TM | Test Mode Output from modem to indicate modem is in |
one of the test modes. | |||
2345
2
3
4
5
Red (Tip)
Green (Ring)
To Terminal | |
Modular Plug | Block Screws |
Fig. F-1. 25-pin to 25-pin RS-232 cable.
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| TD | 3 |
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| RD | 2 |
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| 3 | RD |
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| RTS | 7 |
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| 4 | RTS |
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| CTS | 8 |
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| 5 | CTS |
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| DSR | 6 |
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| 6 | DSR |
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| CD | 1 |
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| 8 | CD |
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| DTR | 4 |
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| RI | 9 |
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| 22 | RI |
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Fig. F-2. 9-pin to 25-pin RS-232 cable.
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