5.21 Control and monitoring of variables with test functionsn For troubleshooting purposes and to display the status of certain variables you canaccess certain test functions via the menu item Debug of the Siemens SIMATIC Man-ager.n The status of the operands and the RLO can be displayed by means of the test func-tion ‘Debug è Monitor’.n The status of the operands and the RLO can be displayed by means of the test func-tion ‘PLC è Monitor/Modify Variables’.n This test function displays the current status and the RLO of the different operandswhile the program is being executed.n It is also possible to enter corrections to the program.n The processing of the states may be interrupted by means of jump commands or bytimer and process-related interrupts.n At the breakpoint the CPU stops collecting data for the status display and instead ofthe required data it only provides the PG with data containing the value 0.n The interruption of the processing of statuses does not change the execution of theprogram. It only shows that the data displayed is no longer valid.When using the test function "Monitor" the PLC must be in RUN mode!For this reason, jumps or time and process alarms can result in the value displayedduring program execution remaining at 0 for the items below:n the result of the logical operation RLOn Status / ACCU 1n ACCU 2n Condition byten absolute memory address SAZ. In this case SAZ is followed by a "?".Overview‘Debug è Monitor’VIPA System 300S+Deployment CPU 317-4PN23Control and monitoring of variables with test functionsHB140 | CPU | 317-4PN23 | en | 18-0182
