Lamps, Touch Switches, Numeral Setting; Notification And Control Of Touch Switches - Omron NT20 User Manual

Lamps, Touch Switches, Numeral Setting

6-5

Lamps, Touch Switches, Numeral Setting

6-5-1

Notification and Control of Touch Switches

Cautions When Bit Input
Is Permitted
This section describes the commands for operating the lamps, touch
switches.
In order to change the display status (lit (flashing) or unlit) of a lamp or touch
switch, use the Lamp and Touch Switch Display Commands. There are two
such commands, one for bit specification and the other for number specifica-
tion.
The Lamp and Touch Switch Display Status Enquiry Command is used to
ascertain the status of a lamp or touch switch. When this command is exe-
cuted the NT20 returns the Lamp/Touch Switch Display Status Response
Command.
Reference
When the status of an NT20 touch switch is changed - for example by press-
ing it - the Touch Switch Number Output Command is sent to the host. When
a numerical value is input by pressing a touch switch to which a numeral set-
ting function has been allocated, a Number Input Notify Command is sent to
the host.
If a touch switch is pressed, the corresponding touch switch number or bit
information is sent to the Host. Conversely, to turn ON a touch switch or cause
it to flash, the touch switch # or bit information is sent from the Host.
The type of data relating to the touch switch notification is specified with the
"bit input attribute" in the screen attributes when creating the screen data with
the Support Tool. It is not permissible to use both notification and control by a
touch switch number and notification and control by bit information on the
same screen.
NT20
Press
START
abcde
Lit
• Bit Touch Switch Method (Bit Input Permitted Setting)
If a touch switch is pressed, bit information is sent according to the position
of the touch switch. It can be used as a normal bit input switch at the PLC.
When this method is used, if more than one touch switch is pressed at the
same time, the information of all the pressed touch switches (0 to 63) is re-
ported to the Host.
• Touch Switch # Method (Bit Input Not-permitted Setting
If the touch switch status is changed, the touch switch number set when
the touch switch is created is sent as a 8-digit hexadecimal number.
If the touch switches are set in the following positions using the Support Tool
while the setting is "bit input permitted", the following operations will occur due
to the configuration of the touch switches.
Take this into consideration when setting touch switch areas.
HOST
Touch switch # or
bit information
Lighting command
Section 6-5
221