Measurement Specialties 9116 - Manual (Page 57)

Pressure Systems, Inc. Model 9116 User’s Manual
Page 48 www.PressureSystems.com
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
Packet
none generated
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