Data Acquisition & Signal Conditioning
A combined universal input signal conditioner, data logger and plotter with some control capability. Conditioning for most sensors or signals requires no additional circuitry.
- Multifunction Data Logger and Chart Recorder
- 8-32 Analogue independently configurable channels
- 16 digital input/output channels for alarms, control, etc
- Accepts mV, V & mA, Thermocouple, PRT, Strain gauge, Thermistor
- Scalable engineering units
- 3 alarms per channel routed to digital outputs
- Configuration via front panel, serial commands or Windows based software
- Records mean, minimum or maximum at 32Hz with output sample rate 8Hz to 6Hours. Sample(s) on demand via internal or external trigger. Sample rate change on alarm.
- Battery backed RTC and internal memory storage
- Data available as ASCII (CSV) file (compatible with most spreadsheet programs)
- Standard Centronics output to printer
- Data transferred to PC via serial (RS232) interface (USB optional)
- Simultaneous 90-240VAC and 10-35VDC operation for loss-free acquisition
- Compatible SDX30 RS232 disk based logger for Gigabyte storage capability
- Chart Recorder Functions for real time printout
- Trace in colour or B&W (depending on printer)
- Plot colour change if alarm triggered
- Individual channel scaling
- Selectable chart speed
- Individual channel identification
- Change of speed on alarm
- Time, date and digital status printed
Ruggedised Data Recorder
The dAtagate QX3 is a ruggedised data recorder developed in association with and marketed by nCode International.
The original system is no longer in production. The SDX range of miniature signal conditioning data loggers, available directly from Pi Logic, offers greatly enhanced capabilities.
The QX3 was the first equivalent to an intelligent tape recorder and signal conditioning system, employing miniature vibration immune hard disks for use where vibration, dust and temperature are problematic. It can record large quantities of data from sources such as strain gauge, thermocouples, pulses or frequencies, with or without a PC used as an on-line display.
The system uses a non-PC processor and operating system to achieve reliability, very low power consumption and immunity to viruses. Early versions used the first shock immune rotating hard disk drives.
For repairs, upgrade to solid-state disks and spares for the QX3, please contact Pi Logic.
For alternatives, please see the SDX range of loggers or the SC16 with built in acquisition and storage.
Signal Conditioning System
Highly flexible multi-channel signal conditioner for lab and mobile use
- Available with or without A/D, simultaneous sample & hold and solid-state disk storage
- Compact (A4 footprint) free standing metal enclosure
- 16 slot backplane accepting independent electronically identifiable signal conditioners
- Range of standard highly flexible electronically configurable conditioners
- Conditioned ±10V outputs suitable for external A/D or other systems
- Wide input isolated DC power supply (9 to 35V), allows operation in 12 and 24V automotive applications
- Up to 16 SC16s can be connected together, providing up to 256 channels of signal conditioning
- PC software (Windows) for set-up, calibration, data download and monitoring via USB/RS232/ Disk
The SDX30 is a range of self-contained data loggers with analogue and/or digital inputs , signal conditioning, A/D conversion and solid-state disk based storage.
- Robust, reliable and flexible solid-state alternative to tape recorder and PC based data acquisition systems
- Standard range and also built to customer's specifications
- Self-contained signal conditioner, A/D, triggering and data storage for analogue and/or digital signals
- Choice of medium or fast storage core allows 0-2K or 0-100K samples per second to be acquired
- Simple tape recorder type operation with removable disks² for configuration and data transfer
- Configurable analogue/digital triggering with pre-event buffer²
- Fast solid-state Compact Flash disk storage with capacities up to the current card limit (> 10GBytes)
- PC Software (Windows) for set-up, calibration, data download and monitoring via USB/RS232/Disk²
- Flexible power supply allowing USB, 5V, 7-35VDC operation with Locking USB/Power cable for mobile use
- LCD/LED displays to indicate logger activity
- Single input connector with large cable clamp/entry for quick logger connection
- Signal conditioners including strain gauge, 4-20mA, F/V, thermocouple, charge, ICP etc
DC-DC Power Supply
LEDs are replacing incandescent and fluorescent lamps in many applications where long life, cool operation, efficiency and display flexibility are important. The powering of individual LEDs, chains of LEDs or LED arrays differs from that of incandescent and fluorescent lamps.
Pi Logic produces a range of efficient constant current output DC-DC converters for driving individual high power LEDs, chains of LEDs or LED arrays. The design caters for variations in supply voltage as well as different number of LEDs in the chain and changes in driving requirements resulting from temperature, ageing and mixed LED type in chains, unlike those with current limiting series resistors.
Most models operate from a nominal 12 or 24V supply from batteries in solar powered, automotive or other application areas.
Some feature a manual brightness adjustment to tailor brightness to field conditions or LED life. Others have photocell control at respond to ambient lighting conditions.
Provide simultaneous sample and hold (S&H) between external signal conditioning and A/D card(s). These units can be used to ensure that all channels on A/D cards are sampled at the same time or ensure that all channels where multiple A/D cards are used, even in different PCs, are sampled at the same time.
Without S&H, the first channel will be sampled before the next and so on. For example; If all channels are driven by a sine wave at even a 1/10th of the sample rate each channel will record a significantly different value. Some A/D cards sample all channels in a burst, which reduces these problems of sample skew but increases potential channel cross-talk. Others spread out the channels throughout the sample to minimise cross-talk, resulting in maximum sample skew.
The S&H operates accepts a trigger pulse, from the A/D card or an external source. On receiving the pulse, S&H holds all current analogue input signal levels and then issues the trigger pulse to fire A/D conversion.
Apart from the obvious benefits, this signal conditioning also removes some of the pitfalls that afflict multiplexed multi-channels A/D cards. Some benefits are;
- Removes A/D sampling skew across single and multiple cards. With multiple cards, one card is designated the Master and issues the trigger pulse which it returned to it and all the other Slave A/D cards when the analogue signals are held.
- Reduction in sample rate is possible where increased sample rate has to be used to counter sample skew
- Low output impedance of the S&H can minimise or eliminate channel cross-talk by reducing the settling time for each channel within the A/D card after it is switched. This can be very bad where high source impedance and gain in the A/D card are used. Unused channels do not float, eliminating “cross-talk” inherited from adjacent channels.
- Provides a robust connection area for A/D card connections
- Protect the A/D card transient or overload damage. Even if damage occurs, the S&H will be easier to repair.
The AAF16 and AAF32 are 16 and 32 channel low-pass filters used as anti-aliasing filters prior to A/D conversion or other filtering tasks.
- 8-pole Butterworth low-pass filters (optional Bessel or Elliptic) with 2-pole guard filter.
- Unity gain in pass-band with ±10V input range
- Independent cut-off frequency for each channel
- Channels can be cascaded, if required
- Fixed frequencies from 1Hz – 20kHz in 1-2-5 steps and frequency synthesiser covering 0.1Hz to 20kHz.
- Coupling for channel can be set to DC, AC (2-pole, 0.3Hz), Bypass or Zero output
- BNC input and output or Custom connectors for A/D card connection, etc
- Mains and DC powered versions available
- Non-volatile setup via PC (RS232 or USB)
Calibration system tailored for use with the SC16 and its plug-in signal conditioners, but suitable for other calibration tasks;
- DC voltage measurement
- DC current measurement
- DC source
- AC voltage source with Sine, Sawtooth, Triangular and Noise waveforms
- Frequency standards
- Thermocouple simulator
- Charge amplifier signal source
- ICP signal source
- Strain gauge breakout terminals and voltage measurement
- Setup via menu, keypad and LCD display or remotely via PC
- Battery powered or external mains adapter
- Rugged diecast aluminium enclosure or miniature portable versions available
- Versions controllable from PC via RS232 or USB
A/D Breakout Boxes
The A/D breakout boxes provide an easy, reliable and robust connection to PC based acquisition cards.
Inputs are normally provided by BNC sockets mounted on the front panel and an appropriate connector on the back for the particular A/D card.
Breakout boxes for most of Data Translations A/D cards are available as standard, including DT28xx, DT300 and 3000 series as well as the external DT98XX USB based cards.
Custom circuitry can be included, if required to manipulate signals; for example
- Passive or active voltage limiters to protect A/D card
- Minimum, Maximum, RMS, etc
- Level displays with meters, bar graph, etc
- Trigger delays or duty cycle adjustment
- External A/D clocks, phase quadrature decoding, debouncing, etc
- Pattern recognition, pulse counting, inversion or elongation, indicators, etc
Some of Pi Logic's specialities are data acquisition signal conditioning LED lighting power steering control
But most importantly because we have lots of in-house manufacturing capability we can rapidly design and prototype whatever you want. We can take things into full production quickly as few people are involved in decision making.
Digital, analogue, power supplies and RF.
Enclosures, mechatronics and chassis.
Windows, Linux, web and embedded.
Code that runs on FPGAs.
In house with SMT and through-hole.
Vertical, horizontal and turning capability.
Specialists in LED lighting solutions.
Research & Development
Decades of experience in R&D projects.
Pi Logic, formerly PIDAS Systems in the U.S.A., was formed in 1987 in response to a demand for data acquisition and specialist instrumentation. It's main objective is research, development and production of electronic instrumentation and services for the industrial field. Since it's formation it has developed and manufactured several product lines from concepts originated within the company or as part of joint projects with other companies.
Pi Logic has had two Stage-1 and one Stage-2 SMART (Small Firms Merit Award for Research and Technology).
Particular areas of expertise are:
- Miniaturised, completely stand-alone data loggers with signal conditioning, processing and on-board solid state storage;
- Signal conditioning front-end for third party A/D cards in PC based data acquisition systems;
- Custom turn-key signal conditioning and data logging systems;
- DC-DC constant current LED drivers for signs, lighting, etc.
Pi Logic has excellent R&D facilities with up-to-date computer systems, machining capability, CAD systems as well as in-house printed circuit board manufacture and assembly. In summary it has all the necessary equipment to take a project from concept to finished product.
Being an SME company is one of Pi Logic's strengths in that it allows for extremely quick turn-around of work since very few people are involved in the decision making process.