Please specify, "system go offline frequently"? do you mean only getting updates every two minutes? or not at all?
Base on your data acquisition settings, you have configured to acquire new records every five minutes(300 seconds) and send data to server every two minutes(120 seconds). If you would want to receive data on your server at a shorter interval, you need to change "send period" interval in data acquisition.
min period - indicates time interval in seconds to acquire new record.
send period - indicates time interval in seconds of sending data to server.
Please see the link below for detail information regarding data acquisition.
Do let me know if this helps.