2
0
1
8
-0
7
30
Configuration
SP_D
The status of SP_D influences the control of the valve. The SP_D variable consists of 2 bytes:
1. The first byte represents the setpoint value of the valve for the
“
auto
”
mode of operation of
the function block.
2. The second byte represents the status.
The setpoint value is only valid if the value of the status byte (second byte) is "GOOD" (NC)-
OK" (80h).
Value
Description
0
Set position
“
closed
”
1 ... 255
Set position
“
open
”
Classic Status Value Mnemonic
Description
0xA0
GOOD (NC)-IFS
(Initiate fail-safe.)
Command for control to change to the
fail–safe state.
0x80
GOOD (NC)-OK
Valid setpoint value.
Recommended to be used as the default
value for "GOOD".
>= 0x40
UNCERTAIN
GOOD (C)
GOOD (NC)
Valid setpoint valueAll values 40h ... BFh
except A0h.
Value 80h recommended to be used
preferably.
<= 0x3F
BAD
All values 00 h ... 3 Fh.
Note!
Controlling the Valve
The setpoint value is not the control value of the valve. Which value opens or closes a valve,
depends on the setting of the "invert setpoint" parameter. For more information, see chapter
8.1.
Example!
Setting the Invert Setpoint Parameter
If the Invert Setpoint parameter is set to "OFF", the setpoint value is not inverted. The setpoint
value "0" controls the valve in the "closed" position. Any other setpoint value from 1 ... 255
controls the valve in the "open" position.
If the Invert Setpoint parameter is set to "ON", the coding of the setpoint value is inverted. That
means, the setpoint value "0" controls the valve in the "open" position. Any other setpoint value
from 1 ... 255 controls the valve in the "closed" position.
