919E EtherNIM Multi-Channel Buffer

• High-performance MCA in a two-wide NIM

• Integral Ethernet connection for instant integration into CONNECTIONS spectroscopy networks

• Four independently-controlled inputs, with independent conversion gains

• 64k-channel data memory, 2³¹–1 (2 billion) counts per channel

• 16k-channel, <7 µs conversion time ADC

• Digital spectrum stabilizer

• Sample changer control port

The ORTEC Model 919E is a member of the EtherNIM family of multichannel buffers. Combined with appropriate computer hardware, ORTEC signal-processing electronics, and ORTEC CONNECTIONS applications software running under Windows 2000/XP, EtherNIM multichannel buffers are the ideal data acquisition hardware for a wide variety of applications in pulse-amplitude spectrometry.

The Model 919E provides the following functions (see block diagram):

1. High-speed, 4-input multiplexer/ router, with individual start/stop/ preset/conversion gain control of each input

2. 16k successive-approximation ADC, with fixed conversion time of <7 µs

3. Digital Spectrum Stabilizer (for input 1 only)

4. Nonvolatile data memory: 64k channels, 2³¹–1 (2 billion) counts per channel

The 919E, a two-wide NIM, is readily connected into an Ethernet environment under Windows 2000/XP. It may be integrated easily into existing networks. Control and spectral display is achieved by the use of a suitable ORTEC CONNECTIONS-32 applications package such as MAESTRO, GammaVision, ScintiVision, AlphaVision, or Renaissance.

The 919E may be employed in two modes: In the first mode, the use of the four independently-controlled inputs make the 919E an extremely cost effective way to configure systems for environmental counting; if required, the full 16k resolution of the ADC is available on each input. Segments need not be set to the same resolution; therefore, a single 919E can support “mixed” detectors, for example NaI and Ge. Each input has its own pile-up rejection and live-time clock circuitry.

In the second mode, the 919E can be used as a single input device for moderate-throughput applications with up to 16k resolution. In this mode the digital spectrum stabilizer is often useful. The dual Direct Memory Access (DMA) architecture employed allows a maximum average data throughput after pileup rejection of ~60,000 counts/sec; the Gedcke-Hale¹ live-time clock ensures high accuracy even well beyond the point of maximum throughput.

The communications protocol used by the 919E is the “traditional” NIM digital bus NIM/488² per DOE/ER-0457T (formerly NIM/GPIB) protocol used for several years in all ORTEC MCB products.³

For the “do-it-yourself” programmer, software toolkits are available to simplify the task of having a user-written application communicate with the Model 919E.

Ordering Information

 ¹Ron Jenkins, R.W. Gould, and Dale Gedcke, Quantitative X-Ray Spectrometry (New York: Marcel Dekker, Inc.), 1981, pp 266–267.

²Please refer to “Standard NIM Digital Bus (NIM/488),” DOE/ER-0457T, U.S. NIM committee, May 1990; Standard NIM Instrumentation System, NTIS, U.S. Department of Commerce, Springfield, Virginia 22161.

³The 919E also provides the ORTEC Dual Port Memory connector on the rear panel. DPM communications are still supported by ORTEC applications packages for historical reasons, but Ethernet communications are recommended in most cases as more convenient (especially over large distances) and, in most cases, less expensive. An RS-232-C port is provided for diagnostic purposes.