Pressure Systems 98RK Delivery of Acquired Data to Host, Network Query and Control Functions

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

The above correction coefficients are maintained internally in IEEE floating-point format. The Read Internal Coefficients ('u') command and the Download Internal Coefficients ('v') command can return (or manually set) calibration coefficients to the host in decimal or hex dump formats in their responses.

3.1.5.4Delivery of Acquired Data to Host

Several commands apply to host delivery of acquired data, either on demand or autonomously. For all Ethernet models, the Read High Precision Data ('r') command may be used to obtain high precision data (in various formats). In addition, Model 9816 provides several high speed, high resolution output commands. The Read High-Speed Data ('b') command is used to read “pure binary” engineering unit pressure (all 16 channels are returned in the lowest overhead format). Use the 'r' and 'b' commands to get acquired data on demand.

The module can also deliver EU pressure data in streams, which consist of TCP/IP data packets that arrive autonomously in the host (with data from selected channels being delivered in various formats at various rates). Up to three independent streams (or time classes) may be configured, started, stopped, and cleared with the Configure/Control Autonomous Host Streams ('c') command. In conjunction with hardware triggering, this autonomous delivery method can also make the module acquire (as well as deliver) data in its most efficient and time-synchronized manner. This also frees the host to receive/process/record these data in its most efficient manner, since it need not waste time continually requesting new data.

Model 9816 also has special purpose on demand data acquisition commands, including: Read Transducer Voltages ('V') and Read Transducer Raw A/D Counts ('a'), which provide two views of raw pressure data. It has similar commands providing EU temperature (￿C) and other raw views of each channel’s special temperature signal, including Read Transducer Temperatures ('t'), Read Temperature A/D Counts ('m'), and Read Temperature Voltages ('n'). This command group is generally used for diagnostic purposes. All of these special purpose data (plus other module status information) may also be periodically delivered to the host automatically in any of the three flexible autonomous streams configured by the 'c' command.

3.1.5.5Network Query and Control Functions

A special subset of three (3) UDP/IP commands may be sent to a module at any time power is applied to it (i.e., neither a host socket connection nor a unique IP Address assignment is required). Each such command is broadcast to all modules (i.e., sent to IP Address 255.255.255.255) via Port 7000, and any module wishing to respond will return a response via Port 7001.

Only one of these commands returns a response. This is the Network Query ('psi9000') command. The others cause the module to be re-booted, therefore no response is possible. One command changes the way the module gets its IP address assignment (i.e., dynamically from a server or statically from factory-set internal data).

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