Please note that many companies manufacturer RS-232 modems but only the HART-Registered modems are guaranteed to have passed the HART Protocol standards and will operate correctly with our tools. USB or other types of modems will not operate with the HART Test System correctly and are not supported. 

We do not make recommendations about specific products to buy. A list of modems can be found on the Product CatalogPlease contact the vendor about purchasing their products displayed in the Product Catalog. 


Replacement parts for the HART Physical Layer Test Kit are available on the tool order form (See HART Physical Layer Test Interface). Note that the modem supplied within the HART Physical Layer Test Kit is augmented with a potentiometer built to our specifications. This modem may be used with the HART Test System if used at the highest potentiometer setting, however it is recommended that this be used only with HSniffer (serial port 1). A commercially available HART-Registered RS-232 modem is required for the test application (serial port 0). See designation of the HART Test System serial ports.