User`s manual

CYDAS UDR Library User’s Guide Analog Input Boards - CYDAS 4020
29
Counter I/O
Counter functions and methods supported
None
Triggering
Trigger functions and methods supported
UDR:
cbSetTrigger()
UDR for .NET: SetTrigger()
Trigger argument values
TrigType TRIGPOSEDGE, TRIGNEGEDGE, TRIGABOVE, TRIGBELOW, GATEHIGH, GATELOW,
GATENEGHYS, GATEPOSHYS, GATEABOVE, GATEBELOW, GATEINWINDOW, GATEOUTWINDOW
Threshold
0 to 4095
Event notification
Event notification functions and methods supported
UDR:
cbEnableEvent(), cbDisableEvent()
UDR for .NET: EnableEvent(), DisableEvent()
Event notification argument values
EventType ON_SCAN_ERROR, ON_PRETRIGGER†, ON_DATA_AVAILABLE, ON_END_OF_AI_SCAN
Hardware considerations
Pacing analog input
Hardware pacing, external or internal clock supported. The clock source can be set via InstaCal to either the
"Trig/Ext Clk" BNC input or the "A/D External Clock" input on the 40 pin connector (P3). Configuring for
the BNC clock input will disable the clock input (pin 10) on the 40-pin connector. When the
EXTCLOCK option
is used, the clock signal presented to the "Trig/Ext Clk" BNC input or the "A/D External Clock" input is
divided by 2 in one or two channel mode and is divided by 4 in four channel mode. If both
EXTCLOCK and
EXTTRIGGER are used, both the Trigger BNC and pin 10 on the 40-pin connector require signals. This is
further explained in the "Triggering and gating" section below. When using
EXTCLOCK, the Rate argument is
used by the CYDAS UDR Library to calculate the appropriate chain size. Set the
Rate argument to the
approximate rate used by the external clock to pace acquisitions.
When executing
cbAInScan()/AInScan() with the EXCLOCK option, the first three clock pulses are used to set
up the CYDAS 4020P, and the first sample is actually taken on the fourth clock pulse.
The packet size varies. See "Memory configuration
" on page 30 for more information.
Triggering and gating
Digital (TTL) hardware triggering supported. The trigger source can be set via InstaCal to either the
"
Trig/Ext Clk" BNC input, the "A/D Start Trigger" input on the 40-pin connector (P3) or the "A/D Stop
Trigger" input on the 40-pin connector (P3). Use the A/D Start Trigger input for the
cbAInScan() and
cbFileAInScan() functions, and AInScan() and FileAInScan() methods. For the cbAPretrig() or
cbFilePretrig() functions, and the APretrig() or FilePretrig() method, use the A/D Stop Trigger
input.
† The EventData for ON_PRETRIGGER events may not be accurate. In general, this value is below the actual number of
pretrigger samples available in the buffer.