Table of Contents
Advertisement
Precautions When Using Local Registers within a User Function
When you call a user function, consider what values could be in the local registers, and perform
initialization as needed.
Name
If input values are not set, the values will be uncertain.
X registers (function
Do not use X registers that are outside of the range that is specified in the input defi-
input registers)
nitions.
If output values are not set, the values will be uncertain.
Y registers (function
Always set the values of the range of Y registers that is specified in the output defini-
output registers)
tions.
When the function is called, the previous settings will be lost and the values will be
uncertain.
Z registers (function
These registers are not appropriate for instructions if the previous value must be
internal registers)
retained.
Use them only after initializing them within the function.
# registers
These are constant registers. Their values cannot be changed.
When the function is called, the previous settings are preserved.
If a previous value is not necessary, initialize the value, or use a Z register instead.
D registers retain the data until the power is turned OFF.
D registers
The default value after restart depends on the setting of the D Register Clear when
Start option. Refer to the following section for details.
• Setting the D Register Clear When Start Option
−
1.
Select File
Environment Setting from the menu bar of the MPE720 Window.
Select Setup − System Setting.
2.
3.
Select Enable or Disable for the D Register Clear when Start Box.
Disable: The initial values will be uncertain.
Enable: The initial values will be 0.
• Setting the D Register Clear When Start Option on page 7-31
7.1 User Program Types and Execution Timing
Precautions
7.1.5 Registers
7
7-31
Advertisement
Table of Contents
Troubleshooting
