When you need to know right away regarding any anomalies in electrical signal, analog voltage, analog current, or the presence or absence of data on an RS485 bus, there’s a system monitoring device that can check and alert-on them all.
The KDMON monitoring device, produced by KK Systems and available from Saelig Company, generates alarms by SMS text message, SMTP email, or fax, and the device can also act as a protocol-independent communications monitor, triggering alarms based on byte sequence or lack of bus activity. It works either on 2-wire RS485 or on either half of a 4-wire RS485 or RS422 system.
Configured via a Windows-based program and external modem, a wide range of alarm conditions and alert options can be selected. The modem choice by the customer depends on the type of alert notification they require for their application. For example, an SMS transmission requires an eternal modem ranging from an industrial GSM model, data-capable GSM, or satellite phone supporting the GSM/Hayes command set.
Once the alarm is responded to, a push button on the front panel of the device resets the LED indicator and all alarms. It operates in this way: the voltage input A/D converter has a resolution of 12 bits and a voltage input range of 33V to _33V. Transducer current (standard 4-20mA transducers) is passed through a 47ohm resistor and it’s the voltage drop across the resistor that is measured using the 12-bit A-D converter. The KDMON requires a 7-35V DC 300mA power supply, and it clips to a standard 35mm DIN rail.
The device is beneficial for limiting downtime as well as early discovery of problems or potential problems and to assist in setting up an emergency notification process to minimize response time.
— Carolyn Mathas is a freelance blogger and editor for EE Times' Industrial Control Designline