Microlink 3000: Modular Measurement and Control

Microlink 3000 is a modular system for measurement and control. The modules plug into a Microlink frame. The 302x range of modules cover totalise counting, frequency counting, up/down counting, start/stop timing and period timing.

There are 3 modules in the range

• 3020 - 8 16-Bit Totalise Counters
• 3021 - 8 16-Bit Frequency and Totalise Counters
• 3022 - 1 24-Bit Timer, Period, Frequency and Up/Down Counter

Microlink 3020 - 8 Totalise (Event) Counters

Each counter on the Microlink 3020 can count up to 65535. You can achieve higher counts by cascading counters together. (A counter produces a voltage pulse when it goes from its maximum count back to zero. You can use this as an input to another counter - thereby continuing the count. In this way you could use two 16-bit counters as a 32-bit counter, counting to 2^32-1 or 4294967295.)

Each counter has a 16-bit output latch. On command from the controlling computer the contents of all counters are simultaneously transferred to their output latches. This means that you can take a snapshot of counter contents at an instant in time, without disturbing the on-going count. This is especially important with cascaded counters. You can set a scale and offset factor to the count with software. For example, if the pulses come from a flow meter which produces one pulse for every 50 millilitres, a scale factor of 0.05 gives a reading in litres.

It is sometimes helpful to count only when a certain condition occurs. For example, if pulses are counted when a machine is running you can calculate the percentage of time the machine is in use just by comparing the total count with the elapsed time. This calculation is simple even though the machine may start and stop many times during the monitoring period, and many machines might be monitored.

All counters have CMOS, TTL and contact closure compatible inputs and can be individually read and reset from software.

Maximum input frequency  10 MHz
TTL and 5 V CMOS compatible

Microlink 3021 - 8 Totalise or Frequency Counters

The Microlink 3021 adds frequency counting to the facilities of the 3020. In totalise mode a counter behaves in the same way as a 3020 counter.

In frequency mode a count is measured over a defined time: the gate time. By dividing the count by the gate time, you can work out the counts per second value, giving a frequency in cycles per second (Hertz). Useful when measuring speed or the immediate rate of power consumption. Four gate times are available: 0.01, 0.1, 1 and 10 seconds. At the end of the gate time the output latches are updated, the count is reset to zero and the measurement restarts.

You can set each counter individually into count or frequency mode from software.

Maximum input frequency  10 MHz
Clock reference          1 MHz crystal oscillator
TTL and 5 V CMOS compatible

Microlink 3022 - 1 Timer, Frequency, Period or Up/Down Counter

The 3022 module provides a single 24-bit counter which you can set from software to be an up/down counter, a frequency counter, a period timer or a start/stop timer.

When set to up/down counter mode, you can control the direction of counting either with software or with a hardware input. A gate input is also available to enable or disable counting. You can use this for applications such as batch counting where the counter would be preset to a starting value and would then count down to zero.

In frequency mode 4 gate times are available: 0.01, 0.1, 1.0 and 10 seconds. The 3022 counts the number of cycles occurring at its input during these gate times.

In period mode the module measures the time for 1, 10, 100 or 1000 cycles of the input signal. The unit of measurement is 0.1 microseconds.

In timer mode the 3022 measures in 0.1 microsecond units the time that a signal is true, or the time between a start and a stop pulse.

Maximum input frequency  10 MHz
Clock reference          10 MHz crystal oscillator
TTL and 5 V CMOS compatible

Software Support

You can control the Microlink 3000 with Windmill, Streamer, SCAN1000 or Excel software. The serial Microlinks (those that communicate over RS232 or RS485) can be OPC-enabled. With the addition of their OPC-server software you can use them with any OPC client software such as Hexatec's Saturn SCADA software and National Instruments' LabVIEW. Another option is to program the Microlink yourself: ask for our programming manuals and example programs.

More Information

For more details on the Microlink 3000 system:

• Send for a free catalogue,
• Download the Microlink Counting and Timing Hardware Manual (pdf format) or
• Contact [email protected].