Comtrol Hub DeviceMaster - Manual (Page 93)

DeviceMaster Installation and Configuration Guide: 2000594 Rev. A Connecting Serial Devices - 93
Connecting Serial Devices
DB9 Loopback Plugs Loopback connectors are DB9 female serial port plugs with pins wired together
that are used in conjunction with application software (Test Terminal or minicom)
to test serial ports. The DeviceMaster is shipped with a a single loopback plug (RS-
232/422).
Note: You can use Test Terminal (Windows) or minicom (Linux) to test the serial
port. You can refer to Testing Ports Using Test Terminal on Page 156 for
Windows systems.
Wire the following pins together to build additional plugs or replace a missing RS-
232 loopback plug:
• Pins 1 to 4 to 6
• Pins 2 to 3
• Pins 7 to 8 to 9
Wire the following pins together for an RS-422 loopback plug:
• Pins 2 to 3
• Pins 7 to 8
Connecting DB9
Serial Devices You can use this information to connect serial devices to DB9 connectors.
1. Connect your serial devices to the appropriate serial port on the DeviceMaster
using the appropriate cable.
Note: Refer to the hardware manufacturer’s installation documentation if you
need help with connector pinouts or cabling for the peripheral device.
2. If the DeviceMaster has Rx/Tx LEDs, verify that the devices are
communicating properly. DeviceMaster 4-port and 8-port models with DB9
ports and the DeviceMaster Serial Hub 16-port provide TX/RX LEDs.
Note: DeviceMaster 1-port and 2-port models do
not have TX/RX LEDs.
The RX (yellow) and TX (green) LEDs function
accordingly when the cable is attached properly to
a serial device.
• After power cycling the DeviceMaster, the RX/TX LEDs are off.
• The LEDs do not function as described until the port has been opened by
an application. You can use Test Terminal to open a port or ports if you
want to test a port or ports (
Testing Ports Using Test Terminal on Page
156).
• If the port is configured for RS-232/422 mode:
- RX LEDs (yellow) are lit
- TX LEDs (green) are lit when as the data exits the port
• If the port is configured for RS-485 mode:
- RX LEDs (yellow) are lit while receiving
- TX LEDs (green) are lit during active data transmission
3. You can refer to Network and Device LEDs on Page 169 for information about
the remaining LEDs.
Pin 1 Pin 5
Pin 6 Pin 9
RS-232 Only
(Back View) The RS-232 loopback plug
also works for RS-422.
Pin 1 Pin 5
Pin 6 Pin 9
RS-422 Only
(Back View)