Emerson Fisher FIELDVUE DVC6000f Instruction Manual page 178

DVC6000f Digital Valve Controllers
RCAS_IN
CAS_IN
BKCAL_IN_1
4
BKCAL_IN_2
BKCAL_IN_1
BKCAL_IN_2
When a BKCAL_IN input sees that its downstream
block is not in Cas mode, the Splitter function block
sets the corresponding OUT value to the BKCAL_IN
value. However, this may not be the same value that
is calculated by the splitter algorithm. When the mode
of the downstream block is changed to Cas, the
difference between the calculated output and the
back-calculation input is computed and the difference
4-118
SP
Auto
Figure 4-18. Output Splitter Function Block Schematic
f
Setpoint
F
f
Limiting
Ç "
CAS_IN f
Shed
"
Mode
F
F
Ç
F
Ç
Ç
F
Ç
Figure 4-19. Output Splitter Function Block Schematic Diagram
IN_ARRAY
OUT_ARRAY
LOCKVAL
Setpoint
SP_WRK
F
"
Rate
SP
Limiting
SP_RATE_DN
SP_RATE_UP
IN_ARRAY
OUT_ARRAY
LOCKVAL
MODE
"
Calculate
Ouput
"
"
Balance
Ouput
"
BAL_TIME
"
Balance
Ouput
"
is added to the calculated output. Next, the difference
is reduced to zero over the time defined by the
BAL_TIME parameter.
When both BKCAL_IN_1 and BKCAL_IN_2 indicate
that the downstream blocks are not in Cas mode or
have Bad status, the first downstream block that goes
to Cas mode causes the upstream block to initialize so
OUT 1
OUT 2
RCAS_OUT
CAS_OUT
Ç
"
BKCAL_OUT
Ç
"
OUT 1
Ç
"
Ç
OUT 2
December 2009