invalid variables of IEC870_103 driver have no value when readvised

invalid variables of IEC870_103 driver have no value when readvised

Summary

issue when IEC870_103 driver has no connection with PLC: after variable(s) with status INVALID was unadvised (e.g. screen with variables was closed or other screen opened based on the same frame) - the re-advised variable has neither value nor timestamp nor status.

Description

issue when IEC870_103 driver has no connection with PLC: after variable(s) with status INVALID was unadvised (e.g. screen with variables was closed or other screen opened based on the same frame) - the re-advised variable has neither value nor timestamp nor status.

Solution

issue was solved by introducing additional internal states in the interface to the TMW Stack used in driver.

Information

workaround - configure variables 'permanently read'

Issue Number: 36419
Fixed on Date: 17.5.2016
Versions: 7.20 0 BUILD 28103