CHAPTER 8: AUTOMATION
AUTOMATION LOGIC
D90
PLUS
LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
477
Figure 403: Latch used in automation logic
About automation virtual outputs
The automation virtual output syntax is shown in the following table.
Table 35: Automation virtual output operators
About automation one-shots
The automation one-shot syntax is shown in the following table.
Table 36: Automation logic one shots
A
one-shot
accepts any digital input or the output of any logical operator. Its output will
assert for one scan following a transition of its input. A negative one-shot will operate on a
falling edge of its input, and a positive one-shot will operate on a rising edge of its input. A
dual one-shot will operate on a rising edge or falling edge of its input. A total of 64 one-
shots are available in the D90
Plus
automation controller.
Figure 404: One-shot used in automation logic
Automation math operators
The automation logic math syntax is shown in the following table. Operators shown with
the
(a, b)
suffix operate on two operands, whereas the others operate on one operand.
Table 37: Automation math operators
Syntax
Description
VDO(1)
to
VDO(96)
Assigns the previous automation logic operand to the corresponding
automation virtual digital output.
VAO1
to
VAO64
Assigns the previous automation logic operand to the corresponding
automation virtual analog output.
Syntax
Description
POSITIVE ONE SHOT
One shot that responds to a positive-going edge.
NEGATIVE ONE SHOT
One shot that responds to a negative-going edge.
DUAL ONE SHOT
One shot that responds to both the positive and negative-going edges.
Syntax
Description
ABS
Return the absolute value of the previous operand.
ACOS
Return the arccosine value of the previous operand.
ADD (a, b)
Add the previous 2 operands.
ASIN
Return the arcsine value of the previous operand.
ATAN
Return the arctangent value of the previous operand.
ATAN2 (a, b)
Return the arctangent value of the first operand divided by the second
operand, with a range of –180 to 180°.
CEIL
Return the smallest integer greater than or equal to the operand.
COS
Return the cosine value of the previous operand.