Scan Table Info
The "Scan Table" property of a channel object sets the frequency for which registers in its RTU's are polled. This screenshot shows the scan table for MasterChannel0 with 2 RTU's, each of which has 3 records in their polls tables. In this example the MasterChannel0 is polling rows 1, 2, and 3 of RTU's 1 & 2 ("Unit Address") at a rate of once per second.
MasterChannel0: 
Micro820 RTU, Unit Address = 2: 