DATA CONVERSION WITH COTS EQUIPMENT Continued from page 67 may also be obtained by the Lynx Converter; for example the pressure altitude validity is bit 11 from word three identified as RT17-R10-03-11. The data from the 1553B bus required by the COTS avionics is shown in Table 2 – MIL-STD-1553B Source Data: Table 2- MIL-STD-1553B Source Data The RT Addressing column of Table 2 indicates that some parameters comprise one word and some comprise two words. In the two-word cases, a most significant word is concatenated with a least significant word to evaluate the parameter. Also shown is that the compass heading and radar altitude parameters are received from six different RT06 receive sub-addresses, three at a time (R01, R02, R03) or (R04, R05, R06). The individual update rates are 8.33 Hz each, but they are equally spaced in time from each other and have fresh values to form an aggregate update rate of 25 Hz. The groups of three switch depending on the operating mode of the aircraft. Data Conversion: The PCU-100 Lynx Protocol Converter is designed as a generic device that can be configured for specific applications using the LynxCom-Pro personal computer software program. The general process to set up data conversion was to define the detailed characteristics of the input and output parameters and then set up the connections between them. LynxCom-Pro provides a hierarchical data tree structure on the left side of the screen, which allows the user to expand input or output objects and specify the associated parameter details (see Figure 2 – LynxCom-Pro Screen). Figure 2 – LynxCom-Pro Screen 68 avionics news • january 2012