The use of loop-powered instruments in process control applications has often meant sacrificing features due to voltage drop limitations on the signal loop. While two-wire devices are cost-effective and easy-to-use, they normally lack advanced display and control capabilities. As a result, loop-powered meters are assumed to be useful for indication purposes only. The introduction of the new Loop Leader PD6600 series loop-powered process meters and rate/totalizers represents a shift away from this common assumption without forgetting their simplicity. The PD6600 series offers output options (solid-state relays, open collectors, and 4-20 mA output), a highly detailed and customizable LCD display, and advanced programming options allowing it to handle a wide range of process control applications. All of this with only a 1.5 V drop on the current loop!
As major as the 4-20 mA loop standard has become in the process control industry, many do not understand the fundamentals of its setup and use. Not knowing the basics could potentially cost you money when it comes time to make decisions about process display and control. This article will define what a 4-20 mA current loop is, break down the components of a 4-20mA loop, and show the pros and cons of using a 4-20 mA loop.
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To register for distributor access on the website existing users can go into their accounts and click on the "edit account" tab and then the "I am a Precision Digital authorized distributor" and fill out the online form. New Users can sign up at https://www.predig.com/user/register. When registering select the "I am a Precision Digital Authorized Distributor" and fill out the online form. Your account will then be reviewed by a sales administrator and you will receive an email notification as soon as your account is setup.
Precision Digital recently introduced three new great ways to monitor your process. The Loop Leader loop-powered meters have been completely redesigned with many innovative features and improvements. The PDW Industrial Wireless Systems provide an easy way to get analog, discrete, or Modbus® signals from where you have them to where you need them. The Helios large display meters and controllers have a super bright, dual-line display that can be read up to 100 feet away, even in bright sunlight. Watch our recently recorded webinar to learn more about these great new products. Visit predig.com/webinars for upcoming webinars.
We love seeing photos of our products in action. So we are offering $50 for photos of our new PDW wireless systems, Helios, or Loop Leader products. We are looking for high resolution photos of the overall process, close-up of the meter, close-up of meter and connected devices, and any additional supporting photos. Click here for full details and rules on the $50 Photo Sweepstakes.
Message for our distributors...
Even if the transmitter has the display, there is still opportunities for a PDC meter. So be sure to ask the customer if they need a meter for the transmitter you're selling.
Precision Digital’s PDW wireless products give you a simple, straightforward way to get analog, discrete, or Modbus® signals from where you have them to where you need them. Our wireless solutions range in complexity from simple point-to-point for wire replacement, to large-scale point-to-multipoint for connecting up to 32 individual field locations to a central base station. Watch the video here.
- Back to Basics Part 2: The Fundamentals of Loop-Powered Devices
- In Depth Look at the PDW Wireless System