551 Board - 16 Analogue Inputs, 2 Analogue Outputs, 16 Digital Inputs/Outputs and 3 CountersThe 551 plugs into the ISA-bus expansion slot of a personal computer. You make your connections to a 37-way D connector, or, if you wish, can permanently wire your signals using an optional boxed screw terminal board.
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Features
- 16 channels of voltage measurement
- 2 voltage output channels
- 16 digital input or output channels
- 3 counting channels
- Supplied with Windmill ready-to-run software for Windows
- Choice of four analogue input ranges, selected from software for each individual channel
- Integrating, on-board, analogue-to-digital converter reduces electrical noise
- Use Windmill to select the resolution of the A-D converter - choose high throughput or high resolution
- Analogue output can act as a programmable attenuator
- Two counting modes
- Chop and change configurations as necessary
- Automatic recalibration
- All results presented in engineering units
- Comprehensive User Manual
- Be up and running in under an hour
Analogue Input Channels
The 551's inputs are multiplexed: Windmill selects one and passes it to the programmable gain amplifier. Four gain ranges are available: x1, x10, x100 and x1000 to a nominal ±10 V input.
The input signal is then passed to an on-board integrating A-D converter. Using Windmill you can select the resolution of each converter, from 12 to 18 bits; so you could choose high throughput, high resolution or optimum noise rejection.
A stable on-board reference voltage is automatically used by the software for recalibration. You can set the recalibration interval to between 1 minute and 24 hours.
Analogue Output Channels
The two 12-bit analogue outputs each produce a voltage output. At power-up or reset the output is always 0 V. Each output can supply 10 mA of current and is short circuit protected.
An output consists of a group of 8 connections on the 37-way D connector. These configure the output as either bipolar or unipolar with maximum ranges of ±10.24 V and 0 to 10.24 V respectively. Smaller ranges can be achieved by dividing down the 10.24 V Reference Out connection with 2 resistors. The full scale range is always controlled by the voltage on the Reference In connection. If this is an AC signal, the channel functions as a programmable attenuator. This signal could be up to 10 kHz in frequency. Alternatively the output of one channel can be fed to the reference input of another channel giving a digital-to-analogue converter with a finely controlled full scale range.
Digital Inputs and Outputs
The 551 provides 16 digital I/O lines, arranged in two ports of 8. Each port can be either input or output. The outputs can drive up to 15 LSTLL loads (6 mA). At power-up all lines are configured as inputs.
Counters
The 551 has 3 16-bit totalling counters. Each counter starts at zero and counts pulses, to a maximum of 65535. You can reset a counter at any time from Windmill software. You can use the counters in two modes: accumulating count and resetting count. In accumulating count the counter keeps counting until you reset it. In resetting count the counter shows the number of pulses since the last reading.
You can set a sale and offset factor to the count from software. For example if the pulses came from a flow meter which produced one pulse for every 50 millilitres, a scale factor of 0.05 would give a reading in litres.
Windmill Data Acquisition Software
The Windmill software lets you be up and running in under an hour. Windmill is a modular suite of software providing, for example, data logging and charting. You can save a library of configuration files making it very quick to start a new test run. Windmill also works with other manufacturers' hardware.
Application Example
A fire station in the Netherlands uses a Microlink 551 to keep them constantly informed of weather conditions. The 551 card collects wind, temperature, pressure and humidity data through its voltage inputs. One of its counters records total rainfall for each 24 hour period. The Windmill Graphics software displays all the data simply and clearly, which is important in emergency situations. The data is available on Network DDE. This means that several weather screens can be displayed around the fire station.
Hardware Specifications
Plugs into the ISA-bus expansion slot of your PC.
16 ANALOGUE INPUTS
Maximum safe input voltage:
Power supply on ±48 V
Power supply off ±33 V
Transient ±300 V
Amplifier:
Ranges (V) ±0.01, ±0.1, ±1, ±10
(set from software individually for each channel)
Common mode range ±13 V
Relative accuracy of ranges:
gain = 1000 ±0.1%
gain = 1, 10, 100 ±0.05%
Analogue to Digital Converter:
Maximum linearity error ±0.02%
Resolution Integration Time Samples/Second*
12 bits 2.5 msec 200
13 bits 5 msec 125
14 bits 10 msec 75
15 bits 20 msec 40
16 bits 40 msec 22
17 bits 80 msec 12
18 bits 160 msec 6
2 ANALOGUE OUTPUTS
Type of output Voltage
D-A resolution 12 bits
Max voltage range ±10.2 V or 0-10.24 V
Current available 10 mA
Max linearity error ±0.025%
Output impedance 0.05 ohm
Power-up state 0 V
16 DIGITAL INPUTS/OUTPUTS
Compatibility TTL and 5 V CMOS, can be made
contact closure compatible
Output capability 15 LSTLL loads
3 COUNTERS
Resolution 16 bits
Max input frequency 3 MHz
Compatibility TTL, 5 V CMOS and contact closure
*Typically 10 samples per second for each channel with Windmill software; so 20 or more channels at 12-bit resolution gives 200 samples per second.
Ordering
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