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
