Know state of PLC program debugging function -

1, start the program status

can be shown in the program editor execute statement table, ladder diagram, or the state of the function block diagram program ( Referred to as program state) To understand the user program execution, the program debugging.

to start the process of program state is as follows: download the compiled program to the CPU; Will switch to the CPU RUN or RUN P mode; Open the logical block, click the button in the toolbar, the state of online monitoring.

test procedure if there is a function at runtime errors or bugs, may cause serious damage to persons or property.

2, statement table program status display

from the cursor selection procedures section began to monitor status. In the statement is shown in figure 1 table editor, on the right side of the window shows the logic operation results after each instruction executed ( RLO） And state the STA ( 状态) 1, an accumulator, 标准) 2, an accumulator, ACCU2) And the status word ( STATUSWORD) , and other content.

in the menu command 'options' - > 'custom' STL TAB in the open dialog box, select the content of the need to be monitored. In 'the LAD/FBD' TAB you can set the ladder diagram ( 小伙子) And the function block diagram ( SFB） Program status display mode.

figure 1 with program status monitoring statements table

3, ladder diagram program status display

ladder diagram and function block diagram with green meet continuous line to indicate the state, that is 'energy flow', as shown in figure 2 on the left side of a thick shallow line; With blue dotted lines said state is not satisfied, can not flow through the; With black straight line shows the state of the unknown.

perform menu commands in the program editor 'options' - > 'custom', in the LAD/FBD TAB you can change the lines and color Settings.

figure 2 ladder diagram program status display

before entering the program state, ladder diagram of the line and components for state is unknown, entirely in black. Start the program after condition monitoring, from the 'power' of ladder diagram on the left side of the vertical line connection are green ( See figure 2) , said have flowed from the 'power' line. Have to flow through the in the closed state of contact, instructions, coil, and the box 'conductor' are expressed in green.

if the CALL instruction calls the logical block successfully, CALL the coil for the green. If jump conditions meet, jump implemented, jump coil for the green. Skipped the instruction of the procedures section is not implemented, these procedures section of trapezoidal the graph is black.

ladder diagram in bold font shows the values of the parameters is the current value of the thin body words show the values of the parameters from the previous cycle, namely the program area in the current scan cycle has not be processed.

4, using the program status function monitoring data block

you must use the way of 'data view' the content of the online data blocks, the online value displayed in the 'actual value' column. Program state is activated, can't switch to a 'declaration view' mode.