User Manual

Control concept
Local control design
5
72 | 351 CM110664en_07
reports the fault and shuts down itself via the back wired output [Dstb]. The pump can only be switched on
again only after the fault is eliminated and the alarm message is reset as required.
The following figure shows a local fault-related shutdown related to superposed plant control. The
compound mapped here as an example was reduced to make is easier to recognize the structure of the
local control.
Local fault-related shutdown of the aggregate depicted here as an example is triggered as follows:
1. A fault is displayed at output [Dstb] when a component valve [Vlv] or pump [Pu1St] reports a fault
(FAULT or OFFNORMAL). The signals revert to enable safety priority [EnSfty] for block BVAL (1).
Fault-related shutdown of all components is triggered via the state output [SftyActv] (2).
2. You can also impact the safety shutdown of the components via the compound interface [I1 EnSfty].
The superposed plant control (not displayed here) can access the object directly via referencing since the
block BVAL is mapped on BACnet and has a priority array [PrioArr]. As a result, plant control can also
trigger a shutdown of the components by commanding the safety priority.
Interlocks
The following figure shows a solution where a fan is only enabled after the damper is completely open.
PrVal Dstb KickDmp
P15 Pgm
P4 Crit
PrVal FbVal Dstb CritActv
TraSta
P15 Pgm P4 Crit
P
r
V
a
l
CritActv Dstb
1
4
:
E
n
P
g
m
1
5
:
V
a
l
P
g
m
1
2
.
E
n
C
r
i
t
1
3
.
V
a
l
C
r
i
t
Off
Ort
Ax:OR
CmdVal Cp:BVAL
Or2 Ax.OR
TCtr
PID_CTR
0%
On
Off
EnCrit ValCrit
Pu 1St:
BO
R/sCtl
Data Sink:
Receives Data
The Information is written by a Client with a
certain priority or is read by the Function Unit.