BA SystemsBAS Building Server is a DIN rail device intended for data collection and presentation of data from all control of BAS series. Data can also be collected from foreign BACnet devices. Read more in databladet.BAS 920 DIOM is a combined I / O and communication modules to suit BAS920. BAS920 DIOM contains 1 M-Bus communication channel, 8 digital inputs and 8 digital outputs. Read more in the data sheet.