RS232 to TTL converter | TTL to RS232 converter
This page describes RS232 to TTL converter and TTL to RS232 converter.
RS232 to TTL converter
Figure-1 depicts simple RS232 to TTL converter. It converts RS232 signal levels to TTL signal levels. Following table-1 mentions RS232 side pin descriptions and signal designations.
| RS232 Pin | Descriptions |
|---|---|
| 2 (RXD) | Receive Data input |
| 3 (TXD) | Transmit Data output |
| 7 (RTS) | Request to Send |
| 8 (CTS) | Clear to Send |
Table-1:RS232 Side Pins
Following table-2 mentions TTL side pin descriptions and signal designations.
| TTL Pin | Descriptions |
|---|---|
| TXD | 3 (Output) |
| RXD | 2 (Input) |
| RTS | 7 (Output) |
| CTS | 8 (Input) |
| GND | 5 (Signal Ground) |
Table-2:TTL Side Pins
TTL to RS232 converter
The TTL to RS232 converter does reverse of the above functionality. It converts TTL signal levels to RS232 signal levels. The same cable as mentioned above can be used with proper mating connectors.
In TTL logic family, logic-1 and logic-0 are represented as follows while RS232 logic levels are represented as follows.
| Logic Type | RS232 | TTL |
|---|---|---|
| Logic 1 ( VIH ) | >+5V (at output), >+2.4V(at input) | 2 V |
| Logic 0 ( VIL ) | <-5V (at output) <0.2V (at input) | 0.8 V |
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