Astronics OMNIBUS II NI PXIe, User Manual

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OMNIBUS II PXIE SPECIFIC FEATURES
OmniBus II NI PXIe User Manual 5-3
5.3 Protocol Sync and Trigger Support
Protocols with Sync and Trigger support (e.g. BTI1553) can interface with the
PXIe Trigger signals by using the
SyncDefine
or
TriggerDefine
functions
(e.g.
BTI1553_BCSyncDefine
,
BTI429_ChTriggerDefine
, etc.). Refer
to Table 5.2 for mappings between protocol triggers (Trigger A-C) and PXIe
Triggers (PXI*). Refer to Table 5.3 for mappings between protocol syncs (Sync
A-C) and PXIe Triggers (PXI*).
Protocol Trigger PXIe Signal Trigger Mask Parameter
A PXI_TRIG[0] TRIGMASK_PXITRIGA
PXIe_DSTARA TRIGMASK_PXISTARA
B PXI_TRIG[1] TRIGMASK_PXITRIGB
PXIe_DSTARB TRIGMASK_PXISTARB
C PXI_TRIG[2] TRIGMASK_PXITRIGC
PXI_STAR TRIGMASK_PXISTARC
Table 5.2—PXIe Trigger to Protocol Trigger Mapping
Protocol Sync PXIe Signal Sync Mask Parameter
A PXI_TRIG[0] SYNCMASK_PXITRIGA
B PXI_TRIG[1] SYNCMASK_PXITRIGB
C PXI_TRIG[2] SYNCMASK_PXITRIGC
PXI_STAR SYNCMASK_PXISTARC
Table 5.3—PXIe Trigger to Protocol Sync Mapping
Triggers are mutually exclusive, however, syncs are not. For example, only
PXI_TRIG[0]
or
PXIe_DSTARA
can be configured at one time to trigger the
protocol logic. In the case of syncs, the protocol logic can drive the sync out to
both
PXI_TRIG[2]
and
PXI_STAR
at the same time.
The OB2 PXIe also extends the protocols’
TriggerDefine
function
capabilities by adding transitional trigger parameters. These new parameters allow
the protocol to be triggered on a high, low, rising, or falling state of the assigned
protocol trigger (A-C). To use this feature, pass the respective parameter found in
Table 5.4 to the
pinpolarity argument of the
TriggerDefine
function (e.g.
BTI1553_BCTriggerDefine
).