Modbus

Statistics

The AADvance controller has a cycle timer and counters to generate statistics for each slave. The statistics are available to the application, enabling to react accordingly or report that a link is operating correctly. These statistics are also used by diagnostic commands. The application reads the statistics as variables (the address of each variable must be specified) and also resets the statistics to zero. Statistics are only available for point-to-point message transfers.

During operation, the statistics are updated on the first message of each slave and on the first slave linked to each master to provide the slave and master cycle times. The

AADvance-Trusted SIS Workstation software®

also verifies the application interface to see if a statistics reset is required.

Meanwhile, the

Modbus®

master measures the overall scan time. A scan measures the time from the start of the first slave until looping back to the first slave, and then a new scan starts. The statistics are updated on the first message of each slave and on the first slave linked to each master to provide the slave and master scan times. The

AADvance-Trusted SIS Workstation software

also verifies the application interface to see if a statistics reset is required.

These application variables also supply diagnostic information, including the status of the communication link and the

Modbus

slave devices connected to the link.