Microlink 3000 Data Acquisition and Control Hardware

The Microlink 3000 is a modular hardware system for data acquisition and control. It offers unrivalled flexibility, allowing almost any instrument or transducer to be connected to a personal computer. With a range of over 40 interchangeable modules, Microlink is equally suited to high or low speed data acquisition or to control, timing or counting operations.

November 2006, M3000-3.2

October 1998, M3000-3.1

Section 10.2 of the Microlink 3000 Hardware Manual, covering opto-isolation for the 3020 and 3021 counting modules, has been updated. It now reads...

The 3801 module enhancer uses opto-isolators to drive the 8 count inputs of the 3020 or 3021 module. The isolator inputs are provided on a row of screw terminals. The inputs can cope with a wide variety of voltages depending on the input resistors used. The standard unit is fitted with 1.5KOhm resistors which produce a switching threshold of about 2.5 to 3V. This low voltage is chosen so that the unit can handle 5V signals. With this standard resistor, you should limit the input voltage to 25V because of the resistor power rating.

Should you wish to change the input resistor, a wire link has been provided for each input immediately behind the screw terminal strip. Remove this link and add additional resistance. The total resistance needed for a particular switching threshold can be simply estimated as:

Threshold Voltage - 1 KOhms

This produces the nominal threshold current of 1mA at the desired voltage. This threshold will not be very accurate due to the spread of opto-isolator characteristics.

The isolators limit the maximum count frequency to about 50KHz.

Microlink 3000 Hardware User Manual

November 2006, M3000-3.2

October 1998, M3000-3.1