Measurement Specialties 9116 user manual St pppp sync per f num

Pressure Systems, Inc. Model 9116 User’s Manual

Command ‘c’— Sub-command Index 00: Configure A Host Delivery Stream

This sub-command is used to configure the principal parameters of each of the three possible concurrent host delivery streams, one at a time. Following this configuration phase, the stream (1, 2, or 3) or all streams may be started and stopped with other sub-commands. The sub- command’s format is:

Command	“c 00 st [[[[p]p]p]p sync per f num”
	‘c’ is the command letter
	‘00’ is the sub-command index (ii) for configuration
	‘st’ is the stream id digit (1, 2, or 3)
	‘[[[[p]p]p]p’ is a 1-4 hex digit position field (channel selection bit map)
	capable of selecting 1-16 internal channels
	‘sync’ is sync type character (0= hardware trigger or 1= clock)
	‘per’ is the period (if sync=0: # of trigger periods or if sync=1: delay timer
	period in msec).
	‘f’ is the format of each acquired datum in stream
	‘num’ is the number of packets delivered in the stream
	(0=unlimited/continuous).
	NOTE: all parameters are separated by a space character.
Response	“A”
	‘A’ is the acknowledge letter
Autonomous	none generated
Packet

Description: Configures a particular stream (‘st’) to deliver data packets autonomously to the host, with each packet containing selected acquired data for the channels specified. The channels are specified by a standard 16-bit position field bit map (encoded as a 1-4 hex digit position field ([[[[p]p]p]p). A separate sub-command (ii=05) may be used to select which acquired data are included in each stream. By default, only pressure (EU) data are selected (if ii=05 sub-command is never executed for the stream).

The individual data packets of the stream may be synchronized with either an external user-supplied hardware trigger or a periodic clock interrupt generated inside each module. This choice is made with the sync type ‘sync’ parameter (a single digit) where: 0 = synchronize with hardware trigger; 1= synchronize with periodic software clock.

When the hardware trigger is used to synchronize data output ( sync = 0), it is assumed that the user would prefer to also synchronize internal data acquisition cycle. For this reason, when a stream utilizing hardware trigger is started, the module firmware switches out of the free-running continuous data acquisition mode described earlier. Instead, the module waits in an idle mode until a hardware trigger is received to initiate a host stream output. Only on the receipt of that hardware trigger will the module scan and EU convert all attached

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