This section gives the pin assignments for IP-Octal Serial connections.
Each channel has five RS-232-C lines. Each channel is wired identically at the 50-pin connector. The five lines are Ground, Transmit Data output, Receive Data input, Ready to Send output, and Clear to Send input. The common ground line for all channels connects to the local logic groud. There are many programming options. The two "modem control lines" RTS and CTS may also be used for other modem or terminal control functions or for general purpose functions.
There is a pullup resistor (1K ) to +12 volts available on pin 42. This may be connected externally to assert a "Mark" (true) signal into an RS-232-C line.
Eight general purpose input lines at non-RS-232 levels are provided on pins 43 through 50. These are unbuffered CMOS logic inputs connected directly to the SCC2698B. They may be programmed as general purpose inputs of as the counter/timer external input. The switching threshold for inputs is at TTL levels (1.5 volts nominal). Since these lines are unbuffered, the user is cautioned to observe anti-static rules in handling cabling, the IndustryPack and all connecting hardware. External equipment connected to these lines should be powered up and down at the same time as the IndustryPack.