When using HART devices in a multi-drop configuration where more than one device is in the loop, each device must be set to a different polling address. The HART Device Addressing App will scan through a range of HART polling addresses to learn the polling address for the connected HART device and then allow you to change it.  

HART Addressing App main screen

The app runs on a Windows PC and connects to your HART device using a HART protocol configuration modem. To set the polling address only one device may be connected at a time. After each device address is set - they can then be wired into the multi-prop configuration.  If only one device will be in your HART loop the polling address should be set to zero to allow for current loop signaling.  If the address is set to anything other than zero the current signaling will be disabled.

When the device is found, the Edit Polling Address dialog will open. The Device Type, ID, HART Rev level, and device Status will be displayed. Type in a new Polling Address and click Save. HART command 6 is used to write the new address to the HART device.

The HART Device Addressing app is included with the HM configuration software free on a CD with the MicroLink-HM or InLink-HM modems.  It is also available for download.

Changing the HART Polling Address