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CD Start Page | DATA ACQUISITION ONLINE Page | DATA ACQUISITION PRODUCTS Page |
For extremely high speed acquisition of data from multiple channels, the DAS-50 and DAS-58 12-bit boards provide a versatile solution. They will sample up to one million samples per second, and can store up to one million samples in on-board memory. This on-board memory guarantees full speed operation of the board regardless of the host computer speed. The DAS-50 has 4 input channels, while the DAS-58 features 8 channels with auto-zero and optional simultaneous sample and hold (SSH) capability. The DAS-58 also has a burst mode, allowing for pseudo-SSH with a 1 ╡s channel-to-channel skew, but without the added expense of the external SSH-58 simultaneous sample and hold accessory.
The DAS-50/58 can be triggered in one of three ways: by software command, external digital input, or by a level on the analog input of channel 0. The boards also offer three trace modes (a trace is a series of samples based on the input triggers). These modes allow you to capture data before, after or around a specific event or trigger condition. The "post- trigger" mode allows the board to acquire N samples after receiving a trigger. "Trace about trigger" mode continuously converts the analog signal until a trigger is received, and then takes N additional samples. This mode is especially useful when looking for data before and after an event has occured. The "pre-trigger" mode continuously takes data, and then stops based on a trigger.
The DAS-58 features an auto-zero capability to ensure accurate measurements. Controlled through software, the auto-zero feature disconnects all inputs and applies zero volts to each input. The inputs are measured and a digital to analog converter (DAC) per channel is used to inject a voltage to correct for any offset. The DACs will maintain these levels until the software executes another auto-zero calibration.
Simultaneous Sample and Hold
The SSH-58 external accessory allows the DAS-58 to operate in a simultaneous sample
and hold (SSH) mode. In this mode, up to eight single-ended inputs are sampled within
▒20 nanoseconds of each other. Channels 0 through 3 or channels 4 through 7 are sampled
with less than 300 picoseconds of inter-channel skew. The SSH-58 uses the burst
mode feature of the DAS-58 to burst sample all channels at 1 ╡s per channel once they
have been held. The first clock pulse is used to hold all channels, so the maximum
aggregate sample rate for 8 channels is 889 ksamples/second. The DAS-58 automatically
performs a zero offset calibration on the SSH-58 when the board is initialized. This helps
insure accurate readings. The
DAS-58 software automatically checks for the presence of the SSH-58, so support is
virtually transparent to
the user.
The SSH-58 has a maximum input range of ▒10 V. The built-in gain of 1/2 gives a maximum output range of ▒5 V. The SSH-58 is housed in a plastic enclosure and it contains BNC connections for all inputs and the external trigger input. The DAS-58 to SSH-58 cable is included. The SSH- 58 is powered from the DAS-58, so no external power is required.
Software Support
DAS-50/58 users can choose between a fully integrated software package (such as
SnapMaster for Windows or Easyest LX), or can write a custom program (in BASIC, C,
Pascal, etc.). The boards are also supported by a comprehensive set of drivers and
programming tools. Two levels of software are available. Provided with each board is the
standard software package, which includes a Call Driver (QuickBASIC compatible), pop-
up control panel which allows mouse or keyboard control and testing of all I/O functions,
installation and configuration program, a variety of example programs which show how to
write DAS-50/58 programs, and a calibration utility.
Also available is the Advanced Software Option, which offers additional software capability beyond the standard software supplied with the board. The ASO includes Call Drivers for Pascal and C, File I/O Drivers for all languages and a Windows 3.X compatible Dynamic Link Library (DLL). This allows the user to program in any language that supports the DLL construct. This includes Visual Basic, Microsoft C, Quick C, Borland C and Turbo Pascal for Windows. Example programs for each language is provided.
VIEW an Adobe Acrobat pdf file for more product info (requires Acrobat Reader).
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