COM 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 COM port, located at the bottom of the JNIOR next to the LAN
Ethernet port, supports a 3-wire serial connection. The default is 115,200
Baud using 8 Data bits, 1 stop bit and no parity. Only software flow control
is available. Flow control is disabled by default.
\ (5) (4) (3) (2) (1) / DB9F Connector Front View
\ (9) (8) (7) (6) /
Pin 2 - Transmit Out (Tx) Active driver output from JNIOR
Pin 3 - Receive In (Rx) from remote system
Pin 5 - Ground reference (GND)
other - No connection.
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.
HELP Topics: MODELS