PLC & Control

TTY-Connect provides everything needed for connecting most teletype machines in up to three local current loops, and for connecting a computer (PC) and/or a radio terminal-unit (TU) via RS-232 serial ports. Power is provided for the TTY loops (and current-limiting), as well as full opto-isolation. Note: this unit is NOT designed to connect to externally-powered loops. You can simply use the unit as a loop supply for connecting multiple TTYs on a loop. Or, you can manually patch a loop to a computer's 232-serial (com) port, allowing a program on the computer to talk to the tty gear. Or, you can manually patch a loop to a radio terminal-unit's 232-serial port, and have the tty gear print the received rtty broadcast. Or, you can include the optional microcontroller to provide programmable signal connections between the loops/TU/PC, data-regeneration, and customizable features like Auto-CR-LF-Insertion, Autostart (motor powering), Selective-Calling, Who-Are-You (WRU), Ascii/Baudot-Conversion, Speed-Conversion, etc. With either the PC232 or TU232 port connected to a tty loop in Full-Duplex mode, the keyboard (or tape-reader) contacts are sensed, and the characters are sent to the 232 port RX line only. Characters from the 232 port TX line are sent to printers (and/or punches). In Half-Duplex mode, typed characters will echo locally on the tty (as well as all other ttys in the loop). Characters sent from the 232 TX line are also echoed on the RX line, since they are returned from the loop sense. Firmware Features When the optional PIC microcontroller is included on the TTY-Connect board, it provides a number of programmable features, and allows “connections” between various “ports” -- the ports are PC232, TU232, HV1 loop, HV2 loop, and LV loop. These features are accessible using commands sent to the PC232 port. Connection Modes Once a connection is made, the unit will power-up in that mode until it is changed (since the connection configuration is stored in non-volatile memory, and is established at power-up). The system provides eight connection modes: 1) Mode-1: Connect the PC232 port in Ascii, to talk Baudot to one of three powered tty loops, or to the TU232 port, at any of the standard tty speeds (60, 66, 75, or 100-wpm). The PC232 port is fixed Ascii at 38400-baud, and uses xon/xoff for data throttling -- the unit automatically converts to/from baudot. The data stream from the PC to the TTY/TU is piped through the baudot “Receive-Stream-Options,” for programmable Auto-CRLFInsertion, AutoStart or SelCal motor powering, Unshift-on-Space, etc. Example: PC connected to M15 on HV1 loop, or Dovetron on TU port... 2) Mode-2: Connect the PC232 port to talk Ascii directly to one of three powered tty loops, or the TU232 port, at a fixed 110-baud. The PC232 port is fixed at 38400-baud, and uses xon/xoff for data throttling. Example: PC connected to M33 on LV loop, or M43 on TU port... 3) Mode-3: Connect the PC232 port to talk raw 5-, 6-, 7-, or 8-bit data to one of three powered tty loops, or the TU232 port, at an adjustable speed (16 to 1000-baud, with 250us resolution). The PC232 port is fixed at 38400-baud, and uses xon/xoff for data throttling. Using 8-bits allows connection to Ascii ttys (M33/35...). Using 5/6/7 bits allows the PC to send/receive custom codes, such as non-ustty 5-level, or 6-level TTS. Example: PC connected to 6-level M20 on HV1 loop... 4) Mode-4: Connect the TU232 port to talk Baudot directly to one of the three powered tty loops, at any of the standard tty speeds (60, 66, 75, or 100-wpm). The TU and TTY must be on the same speed. The data stream from the TU to the TTY is piped through the baudot “Receive-Stream-Options,” for programmable Auto- CRLF-Insertion, AutoStart or SelCal motor powering, Unshift-on-Space, etc. Example: Dovetron TU connected to M15 on HV1 loop, or M28 on HV2 loop... 5) Mode-5: Connect the baudot TU232 port to talk Ascii directly to one of three powered tty loops at a fixed 110- baud. The data stream from the TU to the TTY is piped through the ascii “Receive-Stream-Options,” for programmable Auto-CRLF-Insertion, AutoStart motor powering, etc. Example: TU connected to M33 on LV loop... 6) Mode-6: Connect Baudot ports at DIFFERENT SPEEDS (60, 66, 75, or 100-wpm). A PC must be connected, and running a buffering program, for connecting the high-to-low speed stream. The data stream from Port-A to Port-B is piped through the baudot “Receive-Stream-Options,” for programmable Auto-CRLF-Insertion, AutoStart or SelCal motor powering, Unshift-on-Space, etc. Example: TU at 60-wpm connected to M28 on HV1 loop at 100-wpm Example: TU at 75-wpm connected to M15 on HV2 loop at 60-wpm 7) Mode-10: No connection, but place tty loops in space state (for system testing). 8) Mode-11: No connection, but place tty loops in mark state (for system testing).

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