This is how TrySim names the groups which can be found in the edit masks of the elements with which the connection to the PLC is built up.
The operand can be entered into the little white field either in absolute spelling or as symbol. Names out of the declaration part of blocks that start with ‘#’ are not allowed. I, Q and M as well as the point can also be entered by the number block.
There are interface panels for bits, words and DWords, each panel only accepts operands that (at least in the size) correspond to its type.
In the big white field the comment out of the symbol table is displayed. You can also edit it here. If you have not entered the operand into the symbol table yet this will happen automatically by entering a comment. You cannot assign new symbols or change existing ones in the interface panel, for that you have to open the symbol table.
With the button 
you jump to the cross reference list, in which all uses of the operand in the PLC-program are displayed. By a double click or by the context menu you go from the CR to the desired program position.
With the button 
you jump to the address table in which all further uses of this address in the machine are listed. Please have a look at the points of the context menu as well.
See also: