Presys DCY-2057 Technical Manual page 38

PRESYS
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Instruments
Note that to have a single-loop Controller changed into a dual-loop Controller it
is only necessary to add the optional output cards, since both use the same software.
The control modes selected in this level should be compatible with the output
types installed in the instruments (see section on Connection of Control Output
Signals).
In the DCY-2057 Controller the upper and lower displays always show the
controlled variable and the setpoint/output, respectively, for the control loop 1 or 2.
The values shown on the upper and lower displays will always correspond to the
same control block 1 or 2.
TYPE - this is the option causing the two control blocks 1 and 2 to actuate
either independently or associated. The TYPE selections are:
DUAL - this is the option causing the two control blocks to actuate
independently. This option is used both for single-loop and dual-loop control. Figure
21 below, illustrates the functioning of control blocks for such situation.
INPUT1
INPUT2
Fig. 21 - Conceptual block diagram of control blocks and displays
SP.RE - this is the option for a remote setpoint input. Local setpoint is the
name given to the value of the setpoint selected by the user and manually introduced
by the UP and DOWN keys in the lower display of the Controllers and remote
setpoint is the setpoint introduced via the input 2 of the Controllers. In this case, only
the control block 1 is present, as illustrated on figure 22 below.
INPUT1
SP1
SPR
Fig.22 - Conceptual block diagram of control block and display
DCY - 2057 Pressure Controller
SP1
SP2
for the dual option
for a remote setpoint
OUT1
OUT2
OUT1
Maintenance
Page 36