The POL controllers at a glance
The POL controllers are the modular Climatix controllers from Siemens. They are expanded with extension modules - communication modules on the left, I/O and communication extensions on the right - which makes them suitable for large plants with many data points. Siemens distinguishes two lines:
| POL6xx | POL636, POL638, POL687 |
| POL6x8 | POL648, POL688, POL698 - the more powerful line with BACnet/IP, more simultaneous connections and optional OPC UA and SNMP |
| I/O extension | POL9xx modules on the extension bus, up to 30 m cable length; Siemens recommends up to 10 modules |
| Communication modules | POL90x on the left of the controller, e.g. POL902 Modbus, POL906 LON and others |
| Bus extensions | POL937 M-Bus for heat meters, POL935 OpenTherm |
| Room units | POL822 and QMX3 via process bus, POL824 via Modbus |
| Operation | Operator terminal, smartHMI app (iOS/Android), HMI4Web in the browser, Climatix IC |
Which controller fits depends on the number of data points, bus systems and operating concept. We check this upfront based on the I/O list - and tell you when a compact Climatix S400 is the better choice.