Measurement Computing DaqTemp - Manual (Page 41)

DaqTemp User’s Manual 09-04-02 Specifications 7-3
Input Sequencer
Temperature, voltage, digital and frequency inputs can be scanned synchronously, based on either an internal programmable
timer, or an external clock source. Analog and digital outputs can be synchronized to either of these clocks. Bus Mastering
DMA provides CPU and system-independent data transfers, ensuring data acquisition performance irrespective of other
system activities.
Scan Clock Sources: 2
1. Internal, programmable from 5 us to 5.96 hours in 5 us steps
2. External, TTL level input up to 200 kHz max
Programmable Parameters per Scan: Channel (random order), gain, unipolar/bipolar
Depth: 512 locations
On-Board Channel-to-Channel Scan Rate: 5 µs or 10 µs per channel, programmable
Pacer Clock, also referred to as
External Acquisition Scan Clock Input (A/ICLK and A/OCLK)
Maximum Rate: 200 kHz
Clock Signal Range: 0V to +5V
Minimum Pulse Width: 50 ns high, 50 ns low
Triggering
Trigger Sources: 6, individually selectable for starting and stopping an acquisition. Stop acquisition can occur on a different
channel than start acquisition; stop acquisition can be triggered via modes 2, 4, 5 or 6 described below. Pre-trigger is
supported with fixed or variable pre-trigger periods.
1. Single-Channel Analog Hardware Trigger
Any voltage or TC input channel can be software programmed to be the analog trigger channel
Input Signal Range: -10V to +10V max
Trigger Level: Programmable (11-bit resolution)
Hysteresis: Programmable (11-bit resolution)
Latency: 5 µs max
2. Single-Channel Analog Software Trigger
Any voltage or TC input channel can be selected as the software trigger. If the trigger channel is a thermocouple, then the
driver automatically compensates for the reading delay, resulting in a maximum latency of one scan period.
Input Signal Range: Anywhere within range of the selected trigger channel
Trigger Level: Programmable (16-bit resolution), including “window triggering”
Latency: One scan period max.
3. Single-Channel Digital Trigger
A separate digital input is provided for digital triggering.
Input Signal Range: -15V to +15V
Trigger Level: TTL
Minimum Pulse Width: 50 ns high, 50 ns low
Latency: 5 µs max
4. Digital Pattern Triggering
8- or 16-bit pattern triggering on the digital input port. Programmable for trigger on equal, above, below, or within/outside of
a window. Individual bits can be masked for “don’t care” condition.
Latency: One scan period max.
5. Counter/Totalizer Triggering
Counter/totalizer inputs can trigger an acquisition. User can select to trigger on a frequency or on total counts that are equal,
above, below, or within/outside of a window.
Latency: One scan period max.
6. Software Triggering
Trigger can be initiated under program control.
Analog Output