Functional Test & Data Acquisition I/O Benchmarks
Firewire vs. GPIB vs. MXI-2 vs. VXI Embedded PC
The following benchmarks compare computer I/O performance in functional test and data acquisition applications. The products tested are the Agilent E8491B IEEE-1394 PC to VXI Link, the Agilent E1406A GPIB command module, National Instruments' VXI-PCI8015 MXI-2 VXIbus Interface Kit, and the Agilent E6235A 200 MHz VXI embedded PC.
For comparison purposes, these benchmarks still include the Agilent E8491A to demonstrate the increased speed available with the Agilent E8491B.
- In most applications, the Agilent E8491B provides much better performance than the Agilent E8491A--in others, it is equivalent.
- In most applications, the Agilent E8491B provides much better performance than the Agilent E1406A GPIB command module. The Agilent E8491B is equal to or faster than MXI-2 and embedded PCs when transferring large blocks of data (>64k bytes). Embedded PCs and MXI-2 are faster than the Agilent E8491B when transferring small blocks of data.
- Message-based instruments, such as integrating multimeters, are relatively slow and their measurement times tend to dominate overall test times. I/O time has little impact on overall test times (see benchmarks #2 and #3).
- Choice of I/O is more important when using register-based instruments and test speeds become faster (see benchmarks #4 and #5).
- Choice of I/O is very important in high-speed data acquisition (benchmarks #1 and #6).
- Agilent E1563A digitizer samples a waveform in 1k, 4K, 8K, 16K & 1M samples. (Select the "Benchmark 1" link to view results)
- Agilent E1441A arbitrary function generator outputs a sine wave and the Agilent E1412A DMM measures ac voltage. (Select the "Benchmark 2" link to view results)
- Agilent E1445A arbitrary function generator outputs a waveform and the Agilent E1428A oscilloscope digitizes the waveform. (Select the "Benchmark 3" link to view results)
- Agilent E1330B digital I/O inputs or outputs a control signal, the Agilent E8460A multiplexer opens one switch and closes another, the Agilent E1411B DMM changes function and range then takes 1 reading. This simulates worst-case "peek and poke" measurement time in functional test applications. (Select the "Benchmark 4" link to view results)
- Agilent E1411B DMM and the Agilent E1460A multiplexer form a scanning multimeter. (Select the "Benchmark 5" link to view results)
- Agilent E1413C 64-Channel 100KHz A/D scans multiple channels. (Select the "Benchmark 6" link to view results)