Measurement Computing CIO-DAS6402/12 - Manual (Page 26)

COMPATIBLE MODE:
TRIG0:
Trigger/Gate Enable bit
When = 1, Enables DIN0 input to gate the pacer (external trigger/gate).
When = 0, Enables pacer gate preventing external trigger/gate control.
CTR0:
Counter 0 input control
When = 1, 100 khz input to counter 0 if external counter 0 input is pulled high (or unconnected since the pin is
internally pulled high).
When = 0, external clock input generates pulses to counter 0 clock input.
READ
TRG0 CTR0 - - PACERGATE ARMED POSTMODE - COMPATIBLE
T/G EN T/G SEL T/G POL PRETRIG PACERGATE ARMED POSTMODE - ENHANCED
0 1 2 3 4 5 6 7 Mode
ARMED - When = 0, counting of post-trigger samples is disabled. When = 1, counting of post-trigger samples is enabled.
POSTMODE - SEE REGISTER BASE+8 FOR FULL DESCRIPTION.
PACERGATE - When = 0: the Gate for the 8254 PACER is off. When = 1, the Pacer is on.
5.9 COMPATIBLE MODE CONTROL REGISTER
BASE ADDRESS +11 Example, 30Bh, 779 Decimal
READ/WRITE
GAIN0 GAIN1 HC_AI0 HC_AI1 MODE SE/DIFF UNI/BIP DMA1/3
0 1 2 3 4 5 6 7
Since the DAS6402 has no switches or jumpers, certain options must be selectible for Compatible Mode. This is done by placing
these selections in the Compatible Mode register. The Mode bit must be set to 1 first to allow the following bits to be changed:
DMA1/3, UNI/BIP, SE/DIFF. The default state for all three bits is 0, which is how the DAS1600 is shipped.
DMA1/3 - When = 1, DMA channel 3 is selected.
When = 0, DMA channel 1 is selected.
DMA is allowed only in Compatible Mode, but the DMA channel selection bit can only be changed when the board is in
Enhanced mode. The programmed state will be retained when the board is switched back to Compatible mode.
UNI/BIP - When = 1, Analog Front-End in Unipolar Range
When = 0, Analog Front-End in Bipolar Range
UNI/BIP is used for both Compatible and Enhanced modes, but the bit can only be changed when the board is in
Enhanced mode. The programmed state will be retained when the board is switched back to Compatible mode.
SE/DIFF: When = 1, Analog Front-End in Single-ended Mode
When = 0, Analog Front-End in Differential Mode
SE/DIFF is used for both Compatible and Enhanced modes, but the bit can only be changed when the board is in
Enhanced mode. In Compatible mode, the number of channels is limited according to the table below. The programmed
state will be retained when the board is switched back to Compatible mode.
MODE: When = 1, Board is configured in Enhanced Mode, which in general allows for 64 analog input channels,
enhanced triggering, FIFO/REP INSW support, etc..
When = 0, Board is configured in "Compatible" mode, it is software compatible to the DAS1600.
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