The 232TTL converts RS-232 to TTL levels. Two channels are used to convert from RS-232 to 0 to +5 VDC TTL signals and two channels are used to convert from 0 to +5 VDC TTL signals to RS-232. This converter supports RD, TD, RTS, and CTS. The DB25P male connector (DCE) is for the RS-232 side. The DB25S female connector is for the TTL side.
Pin 7 is signal ground for both connectors. The unit can work at baud rates up to 115K baud. On the RS-232 side, pins 8 (DCD), 20 (DTR), and 6 (DSR) are connected to open pads, if you would rather use these instead of the given RS- 232 lines. Another feature is that the TTL and RS-232 pins can be changed by connecting wires from the pins you want to pads that have been provided. The unit needs a +12VDC power supply (100 mA approx.). A power supply is available from B&B Electronics.
It is important that TTL logic, and only TTL logic (0 to +5 VDC) is used for the TTL side of the converter. The maximum sinking current for one TTL output is 3.2 mA. The maximum source current for one TTL is 1 mA. Signal levels are inverted by the converter. Please refer to table below.
