JANOS Help System: [Commands] [Topics] [Tech Support] [Printable Manual] [Search]
AUX Serial Port Both the COM and AUX (when present) serial ports use a D-sub DB-9F connector defined to be compatible with a a simple M-F DB9 extension cable and connection to a standard PC serial port. Since the latter is rare these days a USB-to-Serial adapter with DB-9M connector can make the connection. The RS-232 AUX port is located at the top of the JNIOR next to the POWER and Sensor Port Expansion Bus connections. In addition to the 3-wire communication connections this port also supports RTS/CTS hardware handshake. The default is 115,200 Baud using 8 Data bits, 1 stop bit and no parity. Both hardware and software flow control are disabled by default. The hardware RTS/CTS lines need no connection for port operation. ---------AUX--------- \ (5) (4) (3) (2) (1) / DB9F Connector Front View \ (9) (8) (7) (6) / ----------------- Pin Assignments Pin 2 - Transmit Out (Tx) Active driver output from JNIOR Pin 3 - Receive In (Rx) from remote system Pin 5 - Ground reference (GND) Pin 7 - Request to Send In (RTS) from remote system Pin 8 - Clear to Send Out (CTS) Active signal output by JNIOR other - No connection. RS-422/RS-485 On the Model 410 the AUX port may be configured for RS-422 or RS-485 operation. The latter allowing applications to fully support 2 and 4 wire full-duplex multi-drop communication networks at up to 250 kBaud. Early Model 410 PCBs included internal jumpers providing an easy way to bridge Receive and Transmit lines for 2-wire RS-485. A third jumper provided the necessary 120 Ohm termination resistor. For proper balancing a termination resistor should be located at both ends of an RS-485 communication line. While the jumper location on the PCB is no longer populated it remains available and may be optionally soldered for this purpose. The bridging and termination resistor can also be externally applied. ---------AUX--------- \ (5) (4) (3) (2) (1) / DB9F Connector Front View \ (9) (8) (7) (6) / ----------------- Pin Assignments (RS-422 and RS-485 Modes) Pin 2 - 485TX (-) Active driver output from JNIOR Pin 3 - 485RX (-) Pin 5 - Ground reference (GND) Pin 7 - 485RX (+) Pin 8 - 485TX (+) Active driver output from JNIOR other - No connection. Proper RS-485 bridging (bi-directional 2-wire communications): * short Pin 2 (485TX-) with Pin 3 (485RX-) * short Pin 8 (485TX+) with Pin 7 (485RX+) * include 120 Ohm resistor between plus (+) and minus (-) lines at transmitter and farthest end of the line. The Java com.integpg.comm.AUXSerialPort class provides support for configuring and controlling the AUX Serial Port. This includes the driver control necessary to support full-duplex 2-wire networking. NOTES The GND is not equivalent to the (-) negative power input in all models except the 412DMX (which requires DC power). This GND floats somewhere between the (+) positive and (-) negative power connections. The JNIOR serial ports are not isolated. Care should be taken not to create unwanted ground loops. SEE ALSO HELP Topics: MODELS, COM_PORT, IOLOG [/flash/manpages/hardware.hlp:212]