Pressure Systems 98RK, 9816 user manual Module Data Acquisition

Pressure Systems, Inc. 98RK-1 & 9816 User’s Manual©

that a power reset has occurred in a module is to notice that the TCP/IP socket connection is no longer valid. At any point during module operation, the Reset ('B') command may be used to return any module to its default “reset” state. If the module is then required to enter any other states (that were previously programmed for it by the host), the host must then restore these states accordingly using the appropriate commands. This reset command simply returns internal software parameters to a default state (as after power up or reboot). It will not close the existing TCP/IP socket (as will power up or reboot).

The Set/Do Operating Options/Functions ('w') command has many purposes, but may first be utilized during the module initialization stage. It may also be executed at any time during data acquisition. However, some non-factory-default options of 'w' may become the new reset default, if a particular function is used to establish them in non-volatile memory.

If any form of the Configure/Control Autonomous Host Streams ('c') command or the Configure/Control Multi-Point Calibration ('C') command was in use before reset, it must be executed again after the reset to restore it. Any other command, that establishes the module in

anon-default reset state, must be re-executed after a reset, if processing is to continue in that state.

The Network Query (“psi9000”) UDP/IP command may be used (at any time) to make each NetScanner™ System module on the network identify itself to the host(s). A parameter, returned in each module’s response, indicates whether or not a module still has a valid connection. This is a useful way to detect if an overt reset occurs in a module. The module may be configured to emit this response automatically after any reset (power on or reboot).

3.1.5.2Module Data Acquisition

After power-up, all NetScanner™ System modules will begin to scan all internal channels in channel number order (16 to 1). Scanning will occur at the module's maximum internal rate (using the previously stored number of data averages per channel). Special external rack (P &

S)channels of the 9816 module are also scanned, but less frequently. The data are stored in an internal buffer, available for retrieval by the host computer. Engineering units conversion of the scanned channels is accomplished (in a separate internal buffer) using thermal correction data extracted from each transducer at power-up. While scanning, the module will automatically monitor the attached transducers’ temperatures, correcting engineering unit output for any temperature effects.

All NetScanner™ System models effectively defer the host computer’s decision of “which channels of data do I want” until the host chooses to send read commands to actually retrieve the desired data from the latest “buffered copy” of the continuously scanned, averaged, and engineering-unit-converted data. See Section 3.1.5.4 (Delivery of Acquired Data to Host) below for more details.

While scanning, all modules take multiple samples and average each channel. The number of samples per internal channel defaults to 8 (eight), but may be set to 1 (one) to disable averaging altogether, or set to any suitable higher value to change the degree of averaging (and its effect on maximum scan rate). The Set Operating Options ('w') command may change this variable at any time. The same command may be used to store the new averaging value as the module’s reset default.

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