wait_digital_input(index, val, timeout=None)
Features
This function waits until the signal value of the digital input register of the controller becomes val (ON or OFF). The waiting time can be changed with a timeout setting. The waiting time ends, and the result is returned if the waiting time has passed. This function waits indefinitely if the timeout is not set.
Parameters
| Parameter Name | Data Type | Default Value | Description |
|---|---|---|---|
index | int | - | A number 1 - 16 which means the I/O index mounted on the controller. |
value | int | - | I/O value
|
timeout | float | - | Waiting time (sec) This function waits indefinitely if the timeout is not set. |
Return
| Value | Description |
|---|---|
0 | Success |
-1 | Failed (time-out) |
Exception
| Exception | Description |
|---|---|
DR_Error (DR_ERROR_TYPE) | Parameter data type error occurred |
DR_Error (DR_ERROR_VALUE) | Parameter value is invalid |
DR_Error (DR_ERROR_RUNTIME) | C extension module error occurred |
DR_Error (DR_ERROR_STOP) | Program terminated forcefully |
Example
PY
wait_digital_input(1, ON) # Indefinite wait until the no. 1 contact becomes ON
wait_digital_input(2, OFF) # Indefinite wait until the no. 2 contact becomes OFF
res = wait_digital_input(1, ON, 3) # Wait for up to 3 seconds until the no. 1 contact becomes ON
# Waiting is terminated and res = 0 if the no. 1 contact becomes ON within 3 seconds.
# Waiting is terminated and res = -1 if the no. 1 contact does not become ON within 3 seconds.