There are several tools that may be used for debugging and testing a communication driver, including snooping software, the VTS Source Debugger (see Source Debugger), and simulators. These tools are described briefly below.
Snooping Software
One useful tool for debugging is serial port or TCP/IP port snooping software, such as Stream Team or Ethereal. This software allows the programmer to view all traffic across the computer's serial or TCP/IP port. The programmer may then verify if the information being sent and received meets expectations.
VTS Source Debugger
VTS comes with a Source Debugger that is very useful in debugging VTS code. It enables programmers to watch variables for value changes, insert breakpoints, and view module content and code. Information on the VTS Source Debugger is provided in Source Debugger.
I/O Device Simulators
Sometimes the actual I/O device hardware is not available to test with the communication software. On such occasions, it is advantageous to write a simulator to emulate the I/O device with which communication is desired. A script application written to use the I/O device's protocol and imitate the I/O device's actions can be run in VTS at the same time as the driver tag. This allows testing of the communication driver without having the I/O device prior to installation on site.