IDEC SmartAXIS Touch FT1A Series

SmartAXIS Touch User’s Manual 20-51
6 Important Notes
20
Script
This section describes important notes when defining a script.
6.1 Important Notes Regarding the While Definition
■ Define so it will not go into an infinite loop.
The execution expression is repeatedly executed while the conditional expression is satisfied.
However, it will go into an infinite loop when the conditional expression is satisfied continually.
In the conditional expression of the while definition, it states to exit the loop when the value of LDR100 turns 0.
However, the value stored in the LDR100 is not changed after storing 10 in the first line of the script, so it will go into
an infinite loop.
When using the while definition, define it so it will not go into an infinite loop.
The value of LDR100 will become 0 when the while definition is repeated 10 times in the next example, and it will get
out of the while definition.
■ Define it so it will not continue the process for longer than the time limit.
In a script of HMI function when the processing of a single script continues for more than the time limit due to a while
definition, etc., an execution time over error occurs and that script will be halted. Define the script so the execution
time for one script does not exceed 3,000 milliseconds.
For details, refer to “1.4 Script Error of HMI Function” on page 20-4.
■ Do not write into the external device address.
In a script of HMI function, a script error occurs when writing to external device addresses in a while definition.
6.2 Number of Devices That Can Be Used
Number of external device addresses that can be set in single script with WindO/I-NV3 are 64 for read device and 64
for write device.
When the total number of write data to an external device address exceeds 64 in a single script while executing a
script with Touch, that script will be halted with an error.
6 Important Notes
[LDR 100] = 10;
while (0 != [LDR 100])
{
[LDR 200] = [LDR 200] + 1;
}
[LDR 100] = 10;
while (0 != [LDR 100])
{
[LDR 200] = [LDR 200] + 1;
[LDR 100] = [LDR 100] - 1;
}