Reaction Time Of Function And Soft Keys; Control Keys As Function Keys; Function Keys Controlling Parallel Outputs; Status Leds In The Function Keys - Omron NT4S Operation Manual

Standard Mode

4.11.3.1 Reaction Time of Function and Soft Keys

4.11.3.2 Control Keys as Function Keys

4.11.4 Function Keys Controlling Parallel Outputs

4.11.5 Status LEDs in the Function Keys

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4. Create the PLC program to perform the following: O 32.0 is to be used to control
the pump
- Evaluate mask number (MW 110); (must have the value 10)
- Create the edge evaluation for M 100.1
- Create the toggle function for pump output O 32.0
- Set flag M 100.0 to 0 when the pump is on
- Set flag M 100.0 to 1 when the pump is off
Whenever function keys need to influence PLC variables, they are given highest
priority when transferred via the protocol. The reaction times during the transfer
procedure are protocol-specific and range from 60 to 120 ms. This is the period of
time which elapses after a key has been pressed until an output is set or reset in the
PLC. The reaction time varies depending on the protocol itself, the load on the
protocol (cyclic data, etc.) and the cycle time of the PLC.
Note that reaction times can be influenced by the polling times of the variables,
messages and images of the LEDs.
Control keys can alternatively be used as function keys to trigger certain actions in
the PLC. They can be defined to carry out the same functions as function keys, i.e.
they are capable of setting (value 1) or resetting (value 0) a variable or of assigning
any values to it. The transfer procedure is independent of the mask parameter
assignment. Thus, if a control key is to carry out a specific function in a mask, it
should not be programmed as a 'mask selector key' at the same time (in other
words, one which initiates a change of mask). The mask-specific evaluation is iden-
tical to that of the function keys.
Groups of 8 function keys can be linked to parallel outputs (semiconductor out-
puts). The keys are read in by the software, debounced and then mapped to the
outputs. The reaction time to the outputs is around 30 ms. As the keys act on the
PLC very quickly and independently of the protocol, they are ideal for controlling
axes or for programming jogging mode.
The power output allows direct control of PLC inputs.
If a PLC variable has been programmed for the function key in addition to the
output, it is of course also sent to the controller, though with a small time delay.
A 2-bit information is provided in the cyclic poll area for each status LED in a func-
tion key. One of the two bits is responsible for activating or deactivating the corre-
sponding status LED while the other bit represents the flash attribute for the status
LEDs. Status LEDs can only be influenced by the controller.
Bit is on/off Bit flashes
0 0
1 0
1 1
0 1
Status of the LED
LED is off
LED is on
LED flashes
LED is off, flash bit can remain set
Section 4-11