Measurement Specialties 9116 DEFINE/CONTROL Autonomous Host Streams Command ‘c’, Ii dddd Command

Pressure Systems, Inc. Model 9116 User’s Manual

DEFINE/CONTROL AUTONOMOUS HOST STREAMS (Command ‘c’)

Purpose: Defines and controls the autonomous delivery of any of up to three concurrent high-speed autonomous data streams to the host computer. Such data streams may be delivered “continuously” without bound (i.e., until a command explicitly stops them), or be delivered in a “limited” amount (until a pre-specified fixed number of data packets have been sent). Each packet delivered may be synchronized by a user-supplied “hardware trigger” or each packet may be delivered periodically as synchronized by an internal software clock. These concurrent host streams are an alternate method of acquiring/delivering data rather than using the Read High-Precision Data (‘r’) command, the Read High- Speed Data (‘b’) command or the many other special purpose read commands (‘V,’ ‘a,’ ‘t,’ ‘m,’ and ‘n,’) for reading alternate data values.

Host data streams, once activated in a module, deliver a sequence of TCP/IP or UDP/IP data packets autonomously to the host (i.e., without the host sending any particular command to the module to request each packet).

WARNING: If these data streams are defined to occur at high rates, then each data packet received by the host must be processed and disposed of in a timely manner. NetScanner™ System modules are capable of generating autonomous data faster than some “slow” hosts (or incapable software) can absorb.

“c ii[ dddd] ... ”

Command

‘c’ is the command letter

‘ii’ is a space + a sub-command index (augment code)

‘dddd’ are one or more optional datum fields, each preceded by a space character which are parameters that differ per augment code ii.

	NOTE: all parameters are separated by a space.
Response	Depends upon particular sub-command (‘ ii’) sent. See below.
Autonomous	Depends upon the particular sub-command
Packet	(‘ ii’) sent. See below.

Description: The firmware of any module, once fully initialized, continuously scans and converts data for all pressure channels at the highest possible speed. The result of such scanning is a continuously updated EU data buffer, available to three concurrent host data delivery tasks, or available to other standard data acquisition commands in the module. Each host delivery task can grab engineering-unit data values from the EU data buffer and deliver them to the host in its own programmable data stream (a sequence of TCP/IP or UDP/IP packets that autonomously arrive in the host, as long as the host has enough TCP/IP buffering space to hold them).

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