Using External Alarms on the T&D RTR-500NW

Activate External Alarms Capability via Digital Contact with the T&D RTR-500NW

Normally the RTR-500NW Ethernet Network Base Station from T&D Corporation is used for network-based alarming and data retrieval. This makes it ideal for remote monitoring of storage temperatures in chambers, refrigerators or freezers. However, in cases where a network is not available, it can also be used to activate a local alarm using the built-in digital contact output. This feature is useful for applications requiring an alarm light or horn such as process monitoring, product testing, and others. With that in mind, CAS DataLoggers Technical Support has put together this quick walkthrough showing how to activate standalone external alarms on your RTR-500NW.  To enable this feature, the RTR-500NW base station must be set up properly. It must first have a static IP set under Network Settings in the RTR-500W Settings Utility (see screenshot below).


It must also have e-mail server settings entered under E-Mail Settings. Neither the e-mail nor the IP settings have to be valid settings for anything, but they need to be present for the 500NW unit to perform properly using the local alarm. (See screenshot below)

Essentially, these settings fool the base unit into thinking it is properly connected to an operable network. Once you have made these settings, all you need to do is to set your high and low alarm settings for the individual loggers and then connect your external alarm to the contact on the RTR-500NW. If you’re using a buzzer or light it is recommended that you use a small relay as electrical isolation.  The contact has a voltage limit of 50 V (AC or DC) and a 100-mA current limit. This document applies to both the Ethernet version of the data collector, the RTR-500NW, and the Wi-Fi version, the RTR-500AW.

T&D Software:

T&D Windows Control Software is designed to help users carry out various functions such as Network Settings, Gather Recorded Data and View Recorded Data in Graphs. Additionally, T&D Graph is available as a free download and allows users to read large numbers of recorded data files into the same graph, merge data, and view/save data in different ways. Additionally, the included T&D WebViewer Application allows users to view current readings, data graphs, and device settings info in a web browser.

About Us:

CAS DataLoggers is a major distributor of data loggers, data acquisition equipment, and paperless chart recorders. We sell directly to end users and maintain a network of distributors and resellers throughout the US. Our Applications Specialists also suggest and provide sensors/transducers and offer value-added services including turnkey systems, calibration, engineering and custom design, and more. Our development capabilities include custom data acquisition and data logging systems, test and measurement systems, programming, and portable data collection systems.

For further information on enabling external alarms on the RTR-500NW Ethernet Base Station or to find the ideal solution for your application-specific needs, contact a CAS Data Logger Technical Specialist at (800) 956-4437 or request more information.

Download our guide on "Choosing the Right Data Logger for Your Application".


CAS DataLoggers offers hundreds of application specific data loggers and universal DAQ systems.

Shop Now

Sign up for our Data Logger Newsletter.