What are my upgrade options for a DAS-1700 Series Board?

What are my upgrade options for a DAS-1700 Series Board?

The DAS-1700 Series offered several varieties each with an available high gain or low gain version. High gain versions such as the DAS-1701ST have programmable gains of 1, 5, 50 and 250; Low gain versions such as the DAS-1702ST have programmable gains of 1, 2, 4 and 8. Additionally, unipolar or bipolar and single ended or differential channel configurations are a standard feature of the cards.

Model	Sample Rate	Resolution	D/A Outputs	D/A Rate
DAS-170xAO	160KHz	12 bits	2	500KHz
DAS-170xHR	50KHz	16 bits	0	n/a
DAS-170xHR-DA	50KHz	12 bits	2	System Dependent - 10KHz
DAS-170xST	160KHz	12 bits	0	n/a
DAS-170xST-DA	160KHz	12 bits	4	System Dependent - 10KHz

In addition to these analog input and output features described in the above table, the boards also have

• 4 digital input lines
• 4 digital output lines

Any upgrade or board replacement should be carefully planned. Often times software and cabling changes are required. Sufficient time should be allowed for complete understanding of the existing system as well as testing of the migrated system to fully discover any subtle differences. Study the documentation for your current system (or reverse engineer it from the wiring and source code) to determine which features of the DAS-1700 Series board are actually in use by the application. Often, only a portion of the board's features are required, so board replacement purely on feature specifications can be misleading.

Upgrading to PCI cards: If the DriverLINX driver was used for code development for the DAS-1700 Series board, then code migration to the KPCI multi function boards will take only moments to complete.

If, however, the code for the DAS-1700 Series was written with other methods (register level, ASO driver for DOS or Windows, etc.), then a rewrite of the controlling software will be necessary. Keithley's PCI cards ship with DriverLINX based support only.

PCI cards are typically memory mapped rather than I/O mapped. Controlling a PCI card from a DOS environment will require use of 32bit DOS extenders for access to the 32bit memory space of the board's registers. Your programming language needs to be able to access the 32bit registers of the card. Furthermore, PCI boards are Plug-and-Play devices so do not have base address switches to control what addresses they inhabit; your program needs to be able to enumerate the PCI bus to detect the card and to read out the assigned address configuration.

Register level control of PCI cards requires a significantly different skill and tool set than was required for ISA boards and often is done with third party tools like WinRT to gain real mode access into 32bit memory space.

Upgrading to Instrument Products: Especially if you have a strong motivation to stay in the DOS operating system, use of the Integra Series Data Acquisition Systems should be considered as an upgrade path. The 27xx mainframes of the Integra Series can be computer controlled via their bus interfaces (RS-232, GPIB or Ethernet) with simple string commands. So in addition to the Windows based IVI drivers and start up software, control from DOS based systems is also quite easy.

While reading rates of Instrument based products are typically slower than plug-in board products, the integrating A/D converters of instruments gives a much greater immunity to noise than plug-in board products. This greater noise immunity eliminates the need for signal averaging which is a common technique required when using plug-in board based systems. The effective sampling rates, especially for temperature monitoring applications, are quite comparable when considering that each single measurement from an instrument will be usable data.

Upgrading to other ISA cards: For minimal impact in terms of both software and cabling, one of the boards in the DAS-1800 Series should be considered. For each model of DAS-1700 Series, there is a corresponding DAS-1800 Series board.

Software written for DAS-1700 will operate with the corresponding DAS-1800 (register compatible).

The DAS-1800 Series boards make use of a faster A/D converter chip so can be operated at faster sampling speeds than the DAS-1700 are rated for. This is the only hardware difference between DAS-1800 and DAS-1700.