A VME: Versa Module Europa, crate controller for high speed data acquisition of heterogeneous, multi-detector systems.

Modern day complex experiments in physics demand highly efficient data acquisition (DAQ) systems capable of acquiring a large number of signals with a very high resolution and near zero dead time, without compromising on the event rate handling capability. To cater to the ever growing demands of the DAQ systems, an intelligent controller with a sequencer and an in-built busy logic has been developed. The heart of the controller is a field programmable gate array that provides (a) a sequencer engine, which holds a list of read-write commands that will be executed upon receiving a valid trigger, (b) a dual port random access memory divided into two blocks of 16 kbytes, each of which is configured in a ping-pong fashion to support data acquisition and data transfer functionalities simultaneously, thereby reducing the dead time, (c) a busy logic interface that validates the master strobe or trigger, a scalar for triggers received, and a time stamp engine for time stamping the events with 10 ns interval, (d) the Versa Module Europa (VME) backplane interface for 32 bit data transfer standards of the VME, and (e) a superspeed universal serial bus communication interface to transfer the data to a computer/single board computer (SBC). The SBC is capable of booting locally or through net via a preboot execution environment from a netboot server, and it contains the driver, libraries, and data server for data collection. A throughput of 32 megabytes per second (MB/s) has been achieved with an event size of 288 signals at an event rate of 30 kiloevents per second with medium slow slave modules, which may further increase up to 45 MB/s with faster slave modules. The VME controller supports an event size (number of signals) of up to 1023 in a single VME crate. Thus, this sequencer engine based VME crate controller development facilitates collection of a high volume of data with a large number of signals at higher event rates and the least dead time; it is named as Readout Ordained Sequencer Engine.

Effects of reducing dietary starch content by replacing barley grain with wheat dried distillers grains plus solubles in dairy cow rations on ovarian function.

Our objective was to evaluate the effects of dietary starch content, altered by partial substitution of dietary grain with wheat dried distillers grain with solubles (DDGS), on the interval from calving to first ovulation, concentrations of hormones and metabolites in plasma and follicular fluid, and granulosa cell gene expression in preovulatory follicles. Sixty lactating dairy cows were assigned to 1 of 2 diets from calving until 84d postpartum. Diets were formulated to contain either 17.3% rolled barley grain (29.2% starch) or 17.2% wheat DDGS (19.1% starch), with 43.0% barley silage and 21.6% rolled corn grain as the other major ingredients (dry matter basis). Transrectal ultrasonography was performed twice weekly to monitor ovarian dynamics from 7 ± 2d postpartum until ovulation or until 56d in milk, whichever occurred earlier. Plasma concentrations of insulin and insulin-like growth factor-1 (IGF-1) were determined in all 60 cows, and that of glucose, fatty acids, and urea in a subset of 24 cows, representing those in which the first ovulation occurred spontaneously within 5 wk postpartum. Estradiol (proestrus) and progesterone (12d postovulation) in plasma were also measured. Concentrations of insulin, IGF-1, glucose, fatty acids, and urea were determined in follicular fluid (wk 9), and the expression of LH receptor, estrogen receptor ß, cytochrome P450 aromatase, and plasma type glutathione peroxidase genes measured in granulosa cells obtained from the preovulatory follicles at wk 9 postpartum in the subset of 24 cows. Diets did not alter the interval from calving to first ovulation (32.3 ± 2.5d), but a significantly lower proportion of cows on the DDGS diet (20%) ovulated multiple (≥ 2) follicles at the first ovulation than those on the barley grain diet (40%). The incidence of multiple ovulations tended to be lower at first insemination (10 vs. 21% for cows fed DDGS and barley grain diets, respectively). Mean plasma concentration of insulin was higher in cows fed the barley grain diet (2.5 vs 1.6 IU/mL), and a diet by time interaction was noted, with cows on the barley grain ration having higher insulin from wk 6 to 12 postpartum; however, mean plasma IGF-1 concentration did not differ between dietary groups. In the subsets, mean plasma concentrations of metabolites or estradiol and progesterone were not affected by diet, parity, or diet by parity interactions. Cows on the DDGS diet had lower concentrations of IGF-I (69 vs. 108 ng/mL) and higher fatty acids (222 vs. 149 mEq/L) in the follicular fluid obtained from preovulatory follicles. Diet, parity, and diet by parity interactions did not affect the concentrations of insulin, glucose, urea, estradiol, and progesterone in follicular fluid. Diets did not alter the expression profiles of LHr, estrogen receptor ß, CYP19, and GPx3 genes in granulosa cells. In summary, diets did not affect the interval from calving to first ovulation or granulosa cell gene expression. However, reducing dietary starch content by a partial replacement of dietary grain with wheat DDGS increased fatty acids in follicular fluid and reduced the concentrations of insulin in plasma, IGF-1 in follicular fluid, and the incidence of multiple ovulations.

A novel time stamping technique for distributed data acquisition systems.

In this paper, we discuss the design and implementation of a synchronizing technique for data acquisition systems, which can effectively use the normal, standard local area network cables to provide a time stamp, with a range up to 32 days, resolution of 10 ns, and synchronization within ± 5 ns. This system may be used to synchronize data being collected by independent heterogeneous data acquisition modules, that acquire events independently. Such distributed systems are generally designed with a tree-like structure or independent self-triggered acquisition boxes. These leaf edges are connected through branches to the root node, via non-bus based inter-connecting links. The present system has been tested with a set of self-triggered digital signal processing based data acquisition engines, having a 100 MHz analog to digital converter front end.

Global Event-identifier Module: a distributed digital approach to event-of-interest identification logic for physics experiments.

The demands from current data acquisition systems are to acquire data from a large number of detectors (or signals) while providing a high throughput. This can be achieved by having some preprocessing capability in the data acquisition system so that it can identify the events of interest. Precise selection of events with minimal time for identification and preprocessing is an experimental challenge. To address this challenge, we have developed a "Global Event-identifier Module" (GEM) on the CAMAC platform, which can flexibly adapt to the experimental requirements and validate an event with minimal time. GEM is a single width CAMAC module capable of operating in a "distributed" data acquisition environment where multiple CAMAC crates (each with one GEM module) can be used to collect synchronized data from all the crates. Event-of-interest decision can be made on signals connected to different crates. Inter-GEM communication is via the ubiquitous ethernet (unshielded twisted pair, CAT5) cable. The event of interest is decided within 32 ns (excluding cable delay). Implementation is accomplished using field programmable gate array which enables greater flexibility for algorithm modifications and updates without hardware changes. GEM supports unified, distributed, and multi-strobe data acquisition, enabling higher throughput, with data collection from a large number of signals by selective reads of events of interest as determined by the experimenter while providing timestamped data of each event.

High precision (14 bit), high density (octal) analog to digital converter for spectroscopy applications.

Nuclear and particle physics experiments with large number of detectors require signal processing and data collection strategies that call for the ability to collect large amount of data while not sacrificing the precision and accuracy of the data being collected. This paper deals with the development of a high precision pulse peak detection, analog to digital converter (ADC) module with eight independent channels in plug-in daughter card motherboard model, best suited for spectroscopy experiments. This module provides multiple channels without cross-talk and of 14 bit resolution, while maintaining high density (each daughter card has an area of just 4.2(")x0.51(")) and exhibiting excellent integral nonlinearity (< or = +/-2 mV or +/-0.02% full scale reading) and differential nonlinearity (< or = +/-1%). It was designed, developed and tested, in house, and gives added advantages of cost effectiveness and ease of maintenance.