Ladder monitor screen display and key functions

6.3 Ladder monitor

The ladder monitor screen display and the keys that are shown at the top of the screen are explained in this section.

6.3.1 Ladder monitor screen display and key functions

The ladder monitor screen varies depending on the type of PLC CPU to be monitored.

After executing PLC read, if the PLC CPU comment or comment capacity is changed, the comment may not be correctly displayed on the ladder monitor screen.

When changing the comment or comment capacity, re-start the GOT.

(1) When MELSEC-A/FX ladder monitor is executed (a) Display

(b) Key functions

This table shows the key functions used with the operations on the ladder monitor screen.

When comment is not displayed : maximum 8 lines When comment is displayed : maximum 3 lines ON/OFF status display for ladder monitor

ON status OFF status

* The MCR command is normally displayed as .

1)

Sequence program is displayed.

A maximum of 11 contact points is displayed in one line of a ladder; for 12 contact points or more, move to the next line.

When a comment display is specified, a comment is also displayed; expanded comments are given priority (For the method of displaying comments, see Sec. 6.3.3.).

2)

A maximum of eight devices is displayed for the word device current value, timer and counter current value (upper row), and set value (lower row). When the set value is an indirect specification, the value of the indirectly specified device is displayed.

(To switch between decimal and hexadecimal for the displayed value, see Sec. 6.3.3.).

3) Display the keys used with the operation on the ladder monitor screen shown in (b) (Touch input).

4) The display step number (left) and the remaining step number (right) are displayed.

Key Function

Return to screen where ladder monitor function starts.

Move to PLC read screen to read sequence program being monitored from PLC CPU (PLC read).

Move to ladder monitor menu screen, to specify sequence program to be displayed on ladder monitor screen (Ladder read).

Start monitoring of sequence program that is displayed on ladder monitor screen.

Activates the List editor function.

(For details of the List editor function, see Chapter 19.)

Switch display device when there are nine or more devices displaying current values and set values.

Display one ladder; scroll up or down.

When reading ladder with device specification, read next program with same device specification (see *2 in Sec. 6.2.2.).

7

Exit PLCRD. Mon. Menu Print

6.3 Ladder monitor

6.3.1 Ladder monitor screen display and key functions 6 - 20

OVERVIEW

2

BEFORE BEGIN- NING OPERATION

3

SPECIFICATIONS

4

OPERATING THE UTILITY FUNCTION

5

OPERATING LAD- DER MONITOR

6

OPERATING THE VARIOUS LADDER MONITOR SCREENS

7

ERROR MESSAGES FOR LADDER MONI- TOR

8

OPERATING SYS- TEM MONITOR

(2) When MELSEC-Q/QnA ladder monitor is executed (a) Display

*1 Depending on the GOT model, a display is provided on the MELSEC-Q ladder monitor screen as indicated below.

A985GOT: Max. 15 lines displayed (1 line: Max. 11 contacts) A956WGOT: Max. 5 lines displayed (1 line: Max. 7 contacts)

*2 When the A985GOT or A956WGOT is used, the operation keys appear on the right side of the MELSEC-Q ladder monitor screen.

(b) Key functions

This table shows the key functions used with the operations on the ladder monitor screen.

When comment is not displayed : maximum 8 lines When comment is displayed : maximum 3 lines ON/OFF status display for ladder monitor

ON status OFF status

* The MCR command is normally displayed as .

1)

Sequence program is displayed.

A maximum of 11 contact points is displayed in one line of a ladder; for 12 contact points or more, move to the next line. *1

When a comment display is specified, a comment is also displayed; expanded comments are given priority (For the method of displaying comments, see Sec. 6.3.3.).

2)

A maximum of eight devices is displayed for the word device current value, timer and counter current value (upper row), and set value (lower row). When the set value is an indirect specification, the value of the indirectly specified device is displayed.

(To switch between decimal and hexadecimal for the displayed value, see Sec. 6.3.3.).

3) Display the keys used with the operation on the ladder monitor screen shown in (b) (Touch input). *2 4) The network No., the station No. and CPU No. are displayed.

5) The drive is displayed.

6) The file name of the PLC program is displayed.

7) The total number of steps in the current monitor PLC program is displayed.

Key Function

Return to screen where ladder monitor function starts.

Move to PLC read screen to read sequence program being monitored from PLC CPU (PLC read).

Move to ladder monitor menu screen, to specify sequence program to be displayed on ladder monitor screen (Ladder read).

Start monitoring of sequence program that is displayed on ladder monitor screen.

Switch display device when there are nine or more devices displaying current values and set values.

Display one ladder; scroll up or down.

When reading ladder with device specification, read next program with same device specification (see *2 in Sec. 6.2.2.).

Displays the search history of the device/contact/coil search or touch search one place backward.

Scrolls the display up or down by ten ladders.

7

Exit PLCRD. Mon. Menu Print

6 - 21 6.3 Ladder monitor

6.3.1 Ladder monitor screen display and key functions About the key

• Immediately after the key has been pressed to go back in the history, a continuous device search using the key cannot be executed.

• Using the key, you can go back into the history up to 100 ladders.

• When any of the following operations is performed, the search history is cleared to return to the normal ladder display.

1. When the key is touched

(When a single ladder block takes up more than one screen, scrolling can be made within the block.)

2. When the key is touched

3. When a step search, END search or defect search is executed 4. When a comment display is changed

5. When a new ladder is read by touching Sea.

Back

Sea.

Back

Sea.

Back

JUMP JUMP

PLCRD.

6.3 Ladder monitor