Delta VP3000 Series - Page 372

Chapter 7 Second Development PlatformVP3000
363
API Instruction code Operand Function
202 SCAL P S
1
, S
2
, S
3
, n
Proportional calculation
Type
Operand
Bit devices Word devices
16-bit instruction (9 steps)
SCAL
Continuous
execution
type
SCALP
Pulse
execution
type
32-bit instruction
- - - -
Associated flag: none
X Y M K H KnX KnY KnM T C D
S
1
  
S
2
  
S
3
  
D

Caution for using operand
 The range of S
1
, S
2
, S
3
is -32768–32767
 If D > 32,767, then D = 32,767
If D < -32,768, then D = -32,768
Description
 S
1
: source value
S
2
: slope (unit: 0.001)
S
3
: offset
D: destination devices
 Operation formula in the instruction: D = (S
1
× S
2
) ÷ 1,000 + S
3
 Users have to obtain S
2
and S
3
(decimals are rounded up into 16-bit integers) by using the
slope and offset formulas below.
 Formula for slope: S
2
= [(max. destination value – min. destination value) ÷ (max. source
value – min. source value)] × 1,000
 Formula for offset: S
3
= min. destination value – min. source value x S
2
÷ 1,000
 Using the formula for slope must be noted that the max. source value has to be greater than
the min. source value, and it’s not limited that the max. destination value to be greater than
the min. destination value.
 The output curve is shown as the figure: