This topic describes how to configure the SCADAPack Modbus driver to scan (poll) SCADAPack Direct controllers for data. Use this information in conjunction with the advanced drivers scanning information (see Scanning Direct Outstations in the ClearSCADA Guide to Advanced Drivers).
To determine how the SCADAPack Modbus driver scans SCADAPack Direct controllers, configure the following:
- Data Packets—Specify the Maximum Packet Size, using the field on the Modbus tab of the Advanced Modbus Channel Form (see Specify the Required Modbus Protocol and Packet Size in the ClearSCADA Guide to the Advanced Modbus Driver).
- Request for an Immediate Poll—Specify if a SCADAPack controller is configured to send an unsolicited message to ClearSCADA, to request an ‘immediate’ poll (see Specify Whether a Channel Uses Unsolicited PLC Functionality in the ClearSCADA Guide to the Advanced Modbus Driver).
- Broadcast Messages.
- Normal and Promoted Scanning—Specify the way in which ClearSCADA retrieves data from most point types on a SCADAPack controller (see Normal and Promoted Scanning in the ClearSCADA Guide to the Advanced Modbus Driver). If your system is running the SCADAPack Modbus RealFLO Extension Driver, refer to the ClearSCADA Guide to the SCADAPack RealFLO Driver for any scanning methodology that differs from that mentioned in this topic.
- Logged Data—Specify whether ClearSCADA is to retrieve DLOG (logged) data for a point, in addition to, or instead of, current data (see Log Point Data on SCADAPack Controllers). Use the Scan Rate field, within the DLOG section of the SCADAPack Controller’s Outstation Form, to specify the frequency with which the driver retrieves any logged data (see Define Whether Logged Data Records are Scanned).