Using Test Functions For The Control And Monitoring Of Variables - Adam 821x Manual

Chapter 3 Deployment of the CPU 821x

Using test functions for the control and monitoring of variables

Outline
Test > Status
3-18
For troubleshooting purposes and to display the status of certain variables
you may access certain test functions via the menu item Test of the

Siemens STEP 7 manager.
The status of the operands and the VKE are displayed by means of the test
function Test > Status.
You are able to modify and/or display the status of variables by means of
the test function PLC > Monitor/control variables.
This test function displays the current signal state and the VKE of the
different operands while the program is being executed.
It is also possible to enter corrections to the program.
Note!
When using the test function Monitoring the PLC has to be in RUN mode!
The processing of states may be interrupted by means of jump commands
or by timer and process-related alarms. At the breakpoint the CPU stops
collecting data for the status display and instead of the required data it only
provides the PU with data containing the value 0.
For this reason jumps or time and process alarms may result in the value
displayed during program execution remaining at 0 for the items below:
• the result of the logical operation VKE
• Status / AKKU 1
• AKKU 2
• Condition byte
• absolute memory address SAZ. In this case SAZ is followed by a "?".
The interruption of the processing of statuses does not change the
execution of the program but it only shows that the data displayed is no
longer valid after from the point where the interrupt occurred.
ADAM 8000 Manual CPU 821x – Rev 1.1
CPU ADAM 821x