Bacnet Communication Watchdog; Fault Monitoring And Resetting; Control Via Bacnet - Grundfos CIM 300 BACnet MS/TP Instructions Manual

Pos. Description
Setpoint 4)
1
(AO, 0)
UserSetpoint 4)
2
(AI, 58)
ActualSetpoint 4)
3
(AI, 9)
X
4
set
5 X
act
4) Percentage of system performance
TPED and MAGNA3-D
The setpoint is written to AO, 0 Setpoint as a percentage value of
the nominal pump frequency, f
nom
in AI, 58 UserSetpoint with the same scaling. From fieldbus, it gets
whatever value is written to Setpoint, but from pump display and the
Grundfos GO, it is truncated to the internal pump frequency limits
[f ; f ].
min max
The actual setpoint, whether it has been set with the Grundfos GO,
the pump display, the pump buttons or the fieldbus, can be read
from AI, 9 ActualSetpoint, and it always reflects the frequency
limitations. It equals the value that the pump actually uses. Values
of f , f and f can be read in the Grundfos GO.
min max nom
1
4 100%
5
6
7
0%
Setpoint in open-loop control for the TPED and MAGNA3-D
Pos. Description
5)
Setpoint
1
(AO, 0)
5)
UserSetpoint
2
(AI, 58)
5)
ActualSetpoint
3
(AI, 9)
f
4
nom
f
5
max
X
6
set
f
7
min
X
8
act
5) Percentage of f
nom

7.3 BACnet communication watchdog

A BACnet communication watchdog is implemented in the CIM/CIU
300 and the CIM/CIU 500. If no BACnet communication is detected
for the time period defined by the BACnet watchdog object (AV, 1),
and the control source of the booster system is set to Bus control
(BO, 0), the CIM 300 makes the booster system run with the
settings defined in local mode.
This functionality can be used for defining the booster system
behaviour in case of a BACnet communication breakdown. Before
enabling the watchdog, the local booster system settings must be
made with either a Grundfos PC Tool or the Grundfos GO (for
Hydro Multi-E only). This ensures that the booster system behaves
as expected if the BACnet communication breaks down.
. The selected setpoint is reflected
2 3
8
When the BACnet communication is re-established after a
watchdog time-out, the booster system runs with the remote
settings again.
When the Present_Value of the AV, 1 object is set to 0, the
watchdog is disabled (default). To enable the watchdog, set the
Present_Value to [5-3600] seconds.

7.4 Fault monitoring and resetting

The following example shows how to monitor faults or warnings in
the booster system and how to manually reset a fault. This option is
not available on the CIM/CIU 500.
The Fault code object (AV, 0) and the Warning code object (AV, 1)
can both hold a Grundfos-specific fault code. See section Grundfos
alarm and warning codes for code interpretation.
Warnings are notifications only, and a warning normally does not
stop the booster system.
If a fault is to be manually reset, use the Reset fault object (BO, 4).
When the Present_Value of this object is set to 1, a Reset fault
command is sent to the device.
Example:
Fault simulation can be helpful for testing alarm behaviour for a
Hydro MPC booster system. The system behaves exactly as if a
real alarm was present.
This example shows how to simulate a "Pressure high" alarm on a
Hydro MPC that results in a stop of all pumps, and requires manual
resetting.
• Set "Simulation event code" (AV, 4) to 210 (Pressure high).
• Set "Simulation device type" (AV, 5) to 8 (System).
• Set "Simulation device number" (AV, 6) to 1 (System).
• Set "Simulation event action type" (AV, 7) to 0 (Stop).
• Set "Simulation event reset type" (AV, 8) to 0 (Manual resetting).
• Set "Fault simulation" (BO, 5) to 1 (Enabled).
• The CU 35X now enters into the system mode "Event action"
and stops all pumps, with the red LED on the CU 35X being on.
On the CU 35X display, the "Pressure high" alarm is indicated.
• Read "Fault simulation status" (BI, 28), and see that it is set to 1
(Fault simulation enabled).
• Remove the simulated alarm settings by setting "Fault
simulation" (BO, 5) to 0 (Disabled).
• Reset the alarm via the CU 35X display or via the BACnet object
"Reset fault" (BO, 4), and the CU 35X goes back to normal
operation.
Related information
12. Grundfos alarm and warning codes

7.5 Control via BACnet

This example shows how to set a Hydro MPC to 50 % setpoint,
constant-pressure mode and bus control.
Before enabling control via the BACnet, values for setpoint, control
mode and operating mode must be set.
• Enable bus control via the CU 35X display. Select "Settings" >
"Secondary functions" > "Control source", then select
"Controlled from bus".
• Set the operating mode with Multistate output 1 (MO, 1). In this
example, the value for operating mode must be 1 (Start).
• Set the control mode with Multistate output 0 (MO, 0). A value of
2 corresponds to Constant pressure.
• Set the setpoint to a value of 50 with Analog output 0 (AO, 0).
See section Setpoint for details on setpoint.
• To enable bus control via the BACnet, set the Binary output 0
(BO 0) to a value of 1.
Now the Hydro MPC should be running at 50 % in constant-
pressure mode with bus control.
Related information
7.2 Setpoint
33