Port Powered TTL / RS-232 Converter

_x000D_ Model 232OTTL converts RS-232 signals to 0-5 VDC TTL ("Transistor-Transistor Logic") levels. The 232OTTL provides 1500V optical isolation. Two channels are used to convert from RS-232 to TTL signals and two channels are used to convert from TTL signals to RS-232._x000D_ _x000D_ These converters support RD, TD, RTS, and CTS. The RS-232 side is a DB25P male connector (DCE). The TTL side is a DB25S female connector. The 232OTTL supports up to 38.4K baud._x000D_ _x000D_ It is important that only TTL logic (0 to 5V) is used for the TTL side of the converter. The maximum sinking current for one TTL output is 8 mA. The maximum source current for one TTL is 0.8 mA. Signal levels are inverted by the converter in its standard configuration as shown in Table 1._x000D_ _x000D_ Model 232OTTL has the option for non-inverted outputs - see Table 2, "Operations Requiring Modification" if non-inverted outputs are desired._x000D_ _x000D_ _x000D_ _x000D_ Port power is derived from the outputs of the host RS-232 port. TD, RTS, and DTR lines may be used to port power the RS-232 side. A minimum of two of these lines in either high or low states is required for proper operation. To externally power the RS-232 side, connect the positive lead of the 12VDC power supply to pin 25 and the GND lead to pin 12 of the DB25 female connector.Model 232OTTL requires both port power on the RS-232 side, and an external 12VDC power supply connected either through 2.5mm jack or pins 12 (GND) and 25 ( 12VDC) on the TTL side.