User`s guide

PCI-2513 User's Guide Specifications
38
Input sequencer
Analog, digital, and counter inputs can be scanned based on either an internal programmable timer or an
external clock source.
Table 5. Input sequencer specifications
Scan clock sources: two (Note 3)
Internal:
 Analog channels from 1 µs to 1 sec in 20.83 ns steps
 Digital channels and counters from 83.33 ns to 1 sec in 20.83 ns steps
External. TTL-level input (XAPCR):
 Analog channels down to 1 µs minimum
 Digital channels and counters down to 83 ns minimum
Programmable parameters per scan
 Programmable channels (random order)
 Programmable gain
Depth
512 locations
Onboard channel-to-channel scan rate
 Analog: 1 MHz maximum
 Digital: 12 MHz if no analog channels are enabled, 1 MHz with analog
channels enabled
External input scan clock (XAPCR)
maximum rate
 Analog: 1MHz
 Digital: 12 MHz if no analog channels are enabled, 1 MHz with analog
channels enabled
Clock signal range
 Logical zero: 0 V to 0.8 V
 Logical one: 2.4 V to 5.0 V
Minimum pulse width
50 ns high, 50 ns low
Note 3: The maximum scan clock rate is the inverse of the minimum scan period. The minimum scan period
is equal to 1 µs times the number of analog channels. If a scan contains only digital channels then
the minimum scan period is 83 ns times the number of digital channels.
Frequency/pulse generators
Table 6. Frequency/pulse generator specifications
Channels
2 x 16-bit
Output waveform
Square wave
Output rate
1 MHz base rate divided by 1 to 65535 (programmable)
High-level output voltage
2.0 V minimum @ –1.0 mA, 2.9 V minimum @ –400 µA
Low-level output voltage
0.4 V maximum @ 400 µA