System One is manufactured in eight standard configurations designated by the product nomenclature SYS-xx or SYS-xxx. The system configuration can be determined from the following desciptions, or from the connector panel figures shown on pages 1-2 to 1 -5. NOTE: The main signal connectors may differ from the XLR types shown in the figures without changing the system configuration. SYS-22 Configuration Dual channel generator and analyzer system. The upper left front panel contains the generator output connectors and the upper right front panel contains the analyzer input connectors. The lower left front panel contains three BNC connectors providing auxiliary signals from the generator. The lower right front panel contains five bnc connectors for monitoring the analyzer signals and connecting an external filter. Blank back panels. SYS-11 Configuration Single channel generator and analyzer system. Otherwise virtually identical to the SYS-22. SYS-20 Configuration Dual channel generator only system with identical functionality as the SYS-22. The upper right front panel contains a pair of 3-pin male XLR connectors to provide interconnection for the generator monitor function. If option "DSP" is installed, the upper right front panel will also contain a 7-pin male XLR connector to provide additional DSP related signal interconnections to a complementary SYS-202 or SYS-302. The lower right front panel is blank. SYS-02 Configuration Dual channel analyzer only system with identical functionality as the SYS-22. The upper left front panel contains a pair of female XLR connectors to provide interconnection to a SYS-20 for the generator monitor function. The lower left front panel is blank. The lower right front panel contains five bnc connectors, identical to the SYS-22 configuration. SYS-222 Configuration "System One + DSP". Dual channel generator and analyzer system including the digital signal processing module for FFTs and other specialized testing. The front panels are identical to the SYS-22 configuration except for the lower left panel which contains six bnc connectors. Blank back panels. SYS-202 Configuration Similar to the SYS-222 except the analog generator is deleted. The upper left front panel contains a pair of 3-pin female XLR connectors to provide interconnection to a SYS-20 for the generator monitor function plus a 7-pin female XLR for DSP related signals. SYS-322 Configuration "System One Dual Domain". Dual channel generator and analyzer system including the digital signal processing module for FFTs and other specialized testing, plus additional capability and connectors for digital signal generation and analysis. The lower left front panel contains a variety of digital audio signal connectors. The lower right back panel contains parallel digital I/O connectors plus bnc connectors for the dsp analog I/O. The lower left back panel contains 3 bnc connectors for the generator auxiliary signals. SYS-302 Configuration Similar to the SYS-322 except the analog generator is deleted. The upper left front panel contains a pair of 3-pin female XLR connectors to provide interconnection to a SYS-20 for the generator monitor function plus a 7-pin female XLR for DSP related signals. 1.3 DIGITAL INTERFACE VERSIONS The System One hardware can not function without host computer control. All systems contain one of three different digital interfaces designated by the letter code "A", "S", or "G" appended to the system configuration nomenclature. Thus, for example, the SYS-322A contains the A-version interface. NOTE: Early production units with serial numbers 10001 to 10299 did not include a letter suffix in their original system nomenclature. These units contain the A-version digital interface. The digital interface option can also be determined by observing the connector types and/or the system configuration decal located on the back chassis panel of System One. Systems with the A-version interface will have either one or two 25-pin D-subminiature connectors labeled with the words "Audio Precision Interface (APIB)". Systems with the S-version interface will have a pair of 25-pin D-subminiature connectors (one for APIB and one for RS-232) plus a DIP switch for baud rate selection. Systems with the G-version interface will have a single 25-pin D-subminiature connector for the APIB, IEEE-488 connector, and a DIP switch for setting the instrument address. A-Version Interface The A-version interface is an 8-bit parallel bus optimized for Audio Precision instrument control. St is referred to as the "APIB" (Audio Precision Interface Bus) throughout this manual. See section 1.4 for more information about the operation of the APIB. Units with the "A" version interface include a digital interface card that is installed in the host computer, a digital interconnection cable, and an extensive software program (SI .EXE) to operate the hardware, create and run tests and procedures, process data, and display results. S-Version Interface The S-version interface provides both APIB and RS-232 control capability (but not simultaneously). Baud rate is selected by rear panel accessible DIP switches. Setting all the baud rate DIP switches to the "up" position activates the APIB. Please note that the APIB must be used when servicing or calibrating a System One. G-Version Interface The G-version interface provides both APIB and IEEE-488 control capability (but not simultaneously). Address selection is set by rear panel accessible DIP switches. Setting all the address DIP switches to the "up" position activates the APIB. Please note that the APIB must be used when servicing or calibrating a System One.