Frontline’s “RS-232 ComProbe II” – A Portable, Rugged and Easy-to-Use Device for monitoring Asynchronous RS-232 communications

RS-232 ComProbe IITo keep pace with advances in technology, the NetDecoder™ analyzer has been upgraded to support the new "RS-232 ComProbe II". Most new laptops and PCs do not have PCMCIA interfaces and the PC industry has migrated towards USB ports. To help our customers monitor asynchronous serial communications via their PC's USB port, Frontline has introduced its new RS-232 ComProbe II. This new RS-232 ComProbe II is a flash drive-sized interface that plugs into a PC's USB port.

The RS-232 ComProbe II monitors and captures Asynchronous RS-232 communications. It does not lose timing and control signal information. With this new interface, Frontline has made its NetDecoder analyzer more rugged, easier to use, portable and transportable. It allows you to spend more time doing your real job.

Monitoring Flexibility

An inline monitoring applicationThe RS-232 ComProbe II provides customers a great deal of flexibility in tapping into Async RS-232 bus configurations to address different monitoring situations.

The RS-232 ComProbe II can be used:

  • Directly in-line or
  • Connected via a combination of a provided Y-cable (enabling a quick connection to permanent or semi-permanent tap into the communication line) and/or the 6 foot RS-232 extension cable.
  • Some monitoring situations may require a pair of 25-pin to 9-pin adapters which are also included in the product.

An example of an in-line asynchronous RS-232 monitoring application is shown here.

I/O Settings

The new RS-232 ComProbe II allows the user plenty of options for monitoring various serial communication setups. The I/O Settings dialog allows the user to configure the setup.

I/O Settings The RS-232 ComProbe II supports data rates up to 921.6Kbps. The user can pick one of the standard rates in the drop down box in the I/O Settings dialog. For non-standard rates, the user can simply type in the value in the box.

The RS-232 ComProbe II can monitor serial communications with 5, 6, 7 or 8 data bits and with 1, 1.5 or 2 stop bits. The device also supports all the standard parity types (None, Odd, Even, Mark, Space, and Ignore).

The user can also choose the bit order on their serial communication circuit. The choices are either LSB (least significant bit) first or MSB (most significant bit) first. LSB first is normal, while MSB first is considered "reversed" from normal. This option reverses the order of the bits within each byte.

The user can also choose to monitor either DTE only, DCE only or both DTE and DCE ends of the communication.

RS-232 ComProbe II Capture Cable Pins Configuration


Connecting one of the unused wires on DB-9 connector pins 1, 4, 6, 7, 8, and 9 to supply power over 0.5A to your device with the RS232 cable could cause serious damage to the RS-232 hardware.

For typical applications only 3 pins on the DB-9 connectors are actually used - pins 2, 3, and 5 for Tx, Rx, and Ground. A DB-9 pin diagram is shown to the right for reference.

To learn more setup and sniffing RS232 networks.

To learn more about how the NetDecoder analyzer can help you. Order your copy of the NetDecoder analyzer today!