# Infrastructure modules

The Boomerang system can use the following infrastructure modules for measurements acquisition. The infrastructure modules are called ‘PC nodes’ in Boomerang system.

| PC node                       | Measurement transmission initiated by: | Measurement received in B2 system by: | Measurement delivered to B2 system via: | Connection to sensor node      |
| ----------------------------- | -------------------------------------- | ------------------------------------- | --------------------------------------- | ------------------------------ |
| S2 PC node                    | B2 server                              | B2 server                             | Serial Port or Virtual Serial Port      | 433MHz S2 radio                |
| S3 PC node                    | B2 server                              | B2 server                             | Serial Port or Virtual Serial Port      | Built into infrastructure node |
| S2 Gateway (S2GW)             | S2GW                                   | B2WEB server                          | HTTP - POST method                      | 433MHz S2 radio                |
| BoomBridgeOne (BBO)           | BBO                                    | B2WEB server                          | HTTP - POST method                      | Built-into infrastructure node |
| Boomerang Backup Logger (BBL) | BBL                                    | B2WEB server                          | HTTP - POST method                      | Built into infrastructure node |
| CoolGuard Gateway (CGGW)      | CGGW                                   | B2WEB server                          | HTTP - POST method                      | 433MHz CG radio                |
| ICU Logger                    | ICU Logger                             | B2WEB server                          | HTTP - POST method                      | Virtual sensor node            |