Data Logging and PC data Link

Question: How can I make the data logging and PC data link for Smart Fieldmeter?

Answer:

Due to a wide variety of applications and patterns of use we chose the analog Remote Monitor output for our instrument.

The output is 0-200 mV, for ranges 0-2 V/m, 0-20 V/m, 0-200 V/m, and 0-60 mV, for range 0-600 V/m.

Maximum output voltages about 300 mV, thus extending the first three ranges output by almost 150% above the maximum display reading (therefore, ranges become: 3 V/m, 30 V/m and 300 V/m.)

Output is balanced, and requires at least 1 MOhm input impedance of the device connected to it. Output must be isolated from instrument case and good AC / RF decoupling is desirable in harsh industrial environments.

We envision three different tasks of data logging:

Task 1

Field measurements are performed for a predetermined time interval, ranging from seconds to hours. Unit must be autonomous while doing measurements, reading and downloading to PC is done at a later time. Indexing and time stamp on each measurement is desirable. Thousands of data points are taken.

Task 2

Field measurements are performed at specified moments of time, initiated by the operator. Indexing and time stamp on each measurement is desirable, so is the ability to review the data without PC. Unit must be autonomous while doing measurements, reading and downloading to PC is done at a later time. Limited number (up to about 30) of data points is taken.

Task 3

Field measurements are performed at fast rate during the EMC immunity testing; continuous data logging into PC is required during the test. PC resident software should be able to acquire the data for display, storage and/or test control.

We suggest the following solutions:

Task 1

1) Portable battery operated data loggers.

For this task we identified the small battery operated data logger that can store up to 8,000 reading. It is reliable and has dual banana input jack. Plug the Remote Monitor cable right into it. EMCTD part number: DL-03.

2) DMM with optically isolated RS232 interface and data logging capability.

For this task we tested two models of multimeter that are rugged versatile devices useful in the lab for general purposes, and capable to be used with Smart Fieldmeter by storing up to 5,400 or 43,000 data points.

The EMCTD part number is DL-01 for the first one (let us know if you want the second one with more memory).

Task 2

2) DMM with optically isolated RS232 interface and data logging memory.

For this task we identified the multimeter with logging memory and time/number stamp feature.

The first model has the ability to take up to 33 readings on request and review them without the PC, plus download to PC later. EMCTD part number is: DL-02. If you need up to 100 data points recorded - we have another model. Just ask.

Task 3

1) Data acquisition cards with fast data logging, differential input and AC/RF decoupling (either optical or transformer).

This is the most critical task for all EMC test labs. We performed an extensive study of various data acquisition systems, both RS232 and USB, looking at usability, RF/AC immunity, software simplicity, features and finally identified the best model to operate with Smart Fieldmeter.

It will allow data streaming with rate of 240 samples/sec, good resolution and excellent decoupling. The supplied software is easily linked to many popular packages from LabView and Visual Basic to Schaffner EMC and others. You will be able to input the data into your application with supplied programming examples.

The EMCTD part numbers are: PCLK-01 (PC Link Kit), and IM-01 (Isolating Input Module). One PCLK-01 unit supports two IM-01 Isolating Input Modules, allowing two units of the Smart Fieldmeter (2 meters with 2 probes) be streaming test data simultaneously. This is very useful when doing RF Radiated Immunity test per MIL 461 standard.

2) DMM with optically isolated RS232 interface and data logging function.

This is simpler solution, useful when PC data streaming is done in a real time but with slower speed. This solution is based on the same multimeters that we selected for the Task 1. The EMCTD part number is DL-01.

These model(s) can perform up to 20 readings/sec in autonomous mode (test duration up to 5 min, and 50 min., correspondingly) and can stream data to PC with rate of 1 reading/second in a real time.

There is a lower cost solution of the multimeter without the logging memory. It can stream data to PC with rate of 1 reading/second in a real time. Ask us, and we will help you to find the best fit for your application.