The EZIO2X4 Inputs use Broadcast messages when there are no links and the Virtual Input Group number is zero (and the Configuration Register is set to enable Broadcast messages). The Inputs use Group On/Off messages when there are links and the Virtual Inputs have the Group number set to match the respective link record regardless of Configuration Register setting. The test for success for the Inputs is whether an Input state change sends a Broadcast message or a Group On/Off message. I did not think Indigo was designed to respond to Group On/Off messages, only looking for Broadcast messages. Group messages are generally more reliable because the Group protocol requires the messages to be ACKed and retired. Broadcast messages are not ACKed and not retired.
The EZIO2X4 Output Relays can be turned On/Off with the Direct commands described in previous posts or the Relays can be turned On/Off with Group commands when links described in this topic been established. The test of the links is to issue Group On/Off commands for the Group numbers defined in those links.
The SHN Utility works with any of the PLM variants including the 2413U USB Dual Band PLM. Simply specify the COM number assigned to the USB port the PLM is connected to. All PLMs support the command set used by the SHN Utility. The Utility does not know if working with a Serial or USB connected PLM. It is simply connecting to a COM port number.