Psim has been designed to minimize
the amount of typing required on the part of the student. To this
end, most instructions are accessed by way of the IBM function
keys F1 through F10. Throughout this documentation, a specific
function key will be referred to as [F1], [F8] etc. The student
should note the definition of each function key is displayed on
the bottom 2 lines of the colour display. Function keys may take
on different definitions depending upon what operation is
currently being executed. Students are encouraged to maintain a
watchful eye on the status lines to see how the [Fn] definitions
change thus minimizing the frustration due to miss-hit keys. The
various functions are grouped together in logical order ensuring
a minimum number of key strokes.
Typing <PSIM> at the DOS
prompt will result in the start-up of the PSIM simulation
program. After a period of initialization the main PSIM
introductory screen will appear which contains the copyright
notice for the PSIM program and an animation of the PSIM logo.
After the animation has completed one cycle, a momentary prompt
will appear stating: 'Press Any Key To Continue'. Pressing a key
at any time while the introductory screen is showing will cause
the main PSIM menu to be displayed. The animation will continue,
but the menu which lists the available choice of process
simulations will remain displayed.
To select one of the process
simulations, simply press the number key on your keyboard that
corresponds to the menu entry you desire.
On each of the process screens the
student will notice that beside each piece of equipment e.g.. The
electric motor in the silo simulation is a label describing the
device i.e.. "Motor" and a PLC I/O address associated
with that device i.e.. "O:1/00". When writing a program
to control pieces of hardware always ensure that the correct I/O
address is used. Please note that all addresses used in this
simulation software use the following convention; the first
character is either an "I" (input) or an "O"
(output), next is a ":" followed by a single digit, a
"/" and finally two digits. This naming convention must
be adhered to if the devices are to be controlled properly.
First level [Fn] key definitions
Once any of the processes have
been selected a new animated process will be displayed. On the
status lines of any of these processes will appear the first of a
series of layers of [Fn] key definitions. With only minor
exceptions all these definitions are the same regardless of which
process is being used. Fig. 2 is a representative sample.
Fig. 2 Process Simulation Menu
keys represent normally open(NO) or normally closed(NC)
momentary switches which may be used at the programmers
discretion for such function as START and STOP buttons to
control the operation of the process. In some processes
there are two such switches and in others there are
to switch from the process display mode to the program
writing mode. Programs are written in the program
creation mode and the tested out in the process display
back to the main menu
taps on this function key will display different areas of
the PLC data table on the screen beside the process. This
function is useful as a program debugging tool
This function is invoked whenever
program creation or modification is required. Do not forget to
"SAVE" the program whenever any changes are made to the
logic. Figs 3 through Fig. 8 depict the [Fn] key definitions used
in the Rung Editor mode.
Fig. 3 Main Editor Menu
||Append, Insert Rung
||Used to Append a new rung
after the current cursor position or to Insert a new rung
ahead of the current cursor position.
||Used to modify an
existing rung.(Fig. 8)
||Used to delete a complete
rung from a program.
||Used to paste back into
the program a rung that had previously been deleted. Used
in combination with [F5] rungs may be moved a rung, in
total, from one area of a program to an other.
||Sub-Menu used to save or
to retrieve user programs.
||Used to completely erase
program memory so that a new program may be written.
||Exit this menu, back to
Fig. 4 Input Instruction Menu
The menu in Fig 4 is activated
whenever Append rung or Insert Rung is requested. The [Fn]
definitions for this menu are:
||Basic input instructions(
see Relay Logic Instructions).
||Branch Start, close
||Used together to form a
series of parallel instructions. Parallel instructions
form a logical OR operation.
||Sub-menu containing all
||back to the main edit
Fig. 5 Output Instruction Menu
The menu in Fig. 5 is activated
whenever an output instruction is requested. The [Fn] definitions
for this menu are as follows (these instructions are more fully
described in "Relay Logic Instructions and Timers and
||Timer on delay
||Count up counter
||Count down counter
||Reinitialize counters and
||Return to main edit menu.
Fig. 6 Word Compare Menu
The menu in Fig. 6 is activated
whenever a Compare Instruction is requested in the main edit menu
Fig. 4. The [Fn] definitions for this menu are as follows (these
instructions are more fully described in "Word Compare
||Word value is equal in
value to a specified immediate value
||Word value is not equal
to a specified immediate value.
||Word value is greater
than a specified immediate value
||Word value is less than a
specified immediate value.
||Word value is greater
than or equal to a specified immediate value.
||Word value is less than
or equal to a specified immediate value.
||Used to select the output
||Menu Used to return to
the main Edit menu
Fig. 7 Utility Menu
The utility menu in Fig. 7 is
activated whenever the unity request is made (Fig. 3). This menu
provides basic functionality for program storage and retrieval.
Program names are not required for these files. File names are
assigned at storage time and these same names are used upon
||Used to save a program so
that it may be retrieved at a later date. File names are
assigned for each process. Files are saved in the default
||Used to re-load a program
that has already been saved ([F1]).
||Used to print a program
to the DOS Device PRN:
||Used to display a
directory of ladder programs saved to date.
||Exit back to main edit
Fig. 8 Rung Modification Menu
The menu in Fig. 8 is activated
whenever a modify rung request is made from (Fig. 3).
Modification implies that the rung already exists, and that some
minor changes are required. The [Fn] key definitions for this
menu are as follows:
||Used to Append (Insert) a
new instruction to the right (Left) of the instruction
under the cursor.
||Used to Delete the
instruction under the cursor.
||Used to Change the
instruction under the cursor. Modifications include
changing the address of the instruction or changing the
||Used to accept the rung
once all of the modifications have been completed