What are my upgrade options for Metrabus?

What are my upgrade options for Metrabus?

Metrabus allows a high number of channels to be added to a computer via a single controller card. The channels of the system were delivered by use of one of various external boards which provided analog input, analog output, digital I/O or relay control boards. Metrabus was easy to program via simple in/out calls to the I/O address space of the controller board.

The Integra Series is an excellent alternative product. Integra maintains the flexibility, high channel count, ease of setup and programming. At the heart of Integra is one of the mainframes: 2700, 2701 or 2750. These DMM-like interfaces provide front panel controls for selection of measurement function, range, etc. The 2700 can accept up to two modules for increased channel count and has standard RS-232 and GPIB interfaces. The 2701 also has two slots but offers both RS-232 and Ethernet interfaces. The 2750 has 5 slots and RS-232 and GPIB interfaces. When used with the 77xx plug-in modules a fully integrated measurement and control system is achieved.

A complete suite of Windows based software and driver support are available for Integra. For customers who may wish to operate in DOS, Linux or other operating system, the SCPI command set is fully documented in the product manuals. Integra can easily be operated from any combination of programming language and operating system.

Although there is no direct replacement for Metrabus, the table below gives a listing of the individual products within Metrabus and some suggested alternatives:

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 present products are actually in use by the application. Often, only a portion of the board's features are required, so product replacement purely on feature specifications can be misleading.

Upgrading to PCI cards: A rewrite of the controlling software will be necessary. Keithley's PCI cards ship with Windows based DriverLINX 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 a measurement system can be a challening task. However, careful planning can ease the burden. Feel free to contact Keithley's Applications Engineering department for advice and to discuss your application requirements. We can help determine that all factors are considered. In the USA, call 888-KEITHLEY (888-534-8453) or 440-248-0400 or contact your local Keithley office (www.keithley.com).