KIN-TEK supplies a Windows executable program named “FlexLink” to monitor and control the generation of multi-component concentrations with the FlexStream gas standards generator. The FlexLink program is provided on CD with shipment of each FlexStream instrument. (Note: FlexLink is not required in order to operate the FlexStream instrument.)

FlexLink communicates with the FlexStream using the industry standard Modbus RTU protocol over serial (RS-232) and/or Ethernet (TCP/IP) physical interfaces.  FlexLink can also interface to RS-485 with addition of an RS-232 to RS-485 converter (not supplied). 

The program continually reads data from the FlexStream, presents the data in various indicators on the PC computer, and allows the user, via the PC, to control the standby, zero and span functions of the FlexStream. Additional functions include viewing the FlexStream configuration, setting oven temperature setpoints and alarm limits, uploading and downloading permeation tube properties to/from the FlexStream and logging acquired data to files.

An added benefit of using Ethernet (TCP/IP) is that the FlexLink program can be run in another room, or even off site, for applications in which the operator needs to be removed from the gas standard generation function. Plus, while one PC may be controlling the FlexStream locally with an RS-232 serial link, another PC may be monitoring the FlexStream remotely via the Ethernet link.

In Figure 1, a target concentration of 1 ppm has been requested. Figure 2 shows the actual generated concentration results for eight permeation tubes that have been loaded into the FlexStream Base module. Figure 3 shows the logged data results.

Figure 1: Setting the target concentration
Figure 2: Generated multi-component gas stream concentrations
Figure 3: Data log